diff --git a/qa/rpc-tests/smartfees.py b/qa/rpc-tests/smartfees.py
index c15c5fda09aa3..ecfffc1b45b43 100755
--- a/qa/rpc-tests/smartfees.py
+++ b/qa/rpc-tests/smartfees.py
@@ -120,15 +120,26 @@ def check_estimates(node, fees_seen, max_invalid, print_estimates = True):
         last_e = e
     valid_estimate = False
     invalid_estimates = 0
-    for e in all_estimates:
+    for i,e in enumerate(all_estimates): # estimate is for i+1
         if e >= 0:
             valid_estimate = True
+            # estimatesmartfee should return the same result
+            assert_equal(node.estimatesmartfee(i+1)["feerate"], e)
+
         else:
             invalid_estimates += 1
-        # Once we're at a high enough confirmation count that we can give an estimate
-        # We should have estimates for all higher confirmation counts
-        if valid_estimate and e < 0:
-            raise AssertionError("Invalid estimate appears at higher confirm count than valid estimate")
+
+            # estimatesmartfee should still be valid
+            approx_estimate = node.estimatesmartfee(i+1)["feerate"]
+            answer_found = node.estimatesmartfee(i+1)["blocks"]
+            assert(approx_estimate > 0)
+            assert(answer_found > i+1)
+
+            # Once we're at a high enough confirmation count that we can give an estimate
+            # We should have estimates for all higher confirmation counts
+            if valid_estimate:
+                raise AssertionError("Invalid estimate appears at higher confirm count than valid estimate")
+
     # Check on the expected number of different confirmation counts
     # that we might not have valid estimates for
     if invalid_estimates > max_invalid:
@@ -184,13 +195,13 @@ def setup_network(self):
         # NOTE: the CreateNewBlock code starts counting block size at 1,000 bytes,
         # (17k is room enough for 110 or so transactions)
         self.nodes.append(start_node(1, self.options.tmpdir,
-                                     ["-blockprioritysize=1500", "-blockmaxsize=18000",
+                                     ["-blockprioritysize=1500", "-blockmaxsize=17000",
                                       "-maxorphantx=1000", "-relaypriority=0", "-debug=estimatefee"]))
         connect_nodes(self.nodes[1], 0)
 
         # Node2 is a stingy miner, that
-        # produces too small blocks (room for only 70 or so transactions)
-        node2args = ["-blockprioritysize=0", "-blockmaxsize=12000", "-maxorphantx=1000", "-relaypriority=0"]
+        # produces too small blocks (room for only 55 or so transactions)
+        node2args = ["-blockprioritysize=0", "-blockmaxsize=8000", "-maxorphantx=1000", "-relaypriority=0"]
 
         self.nodes.append(start_node(2, self.options.tmpdir, node2args))
         connect_nodes(self.nodes[0], 2)
@@ -229,22 +240,19 @@ def run_test(self):
         self.fees_per_kb = []
         self.memutxo = []
         self.confutxo = self.txouts # Start with the set of confirmed txouts after splitting
-        print("Checking estimates for 1/2/3/6/15/25 blocks")
-        print("Creating transactions and mining them with a huge block size")
-        # Create transactions and mine 20 big blocks with node 0 such that the mempool is always emptied
-        self.transact_and_mine(30, self.nodes[0])
-        check_estimates(self.nodes[1], self.fees_per_kb, 1)
+        print("Will output estimates for 1/2/3/6/15/25 blocks")
 
-        print("Creating transactions and mining them with a block size that can't keep up")
-        # Create transactions and mine 30 small blocks with node 2, but create txs faster than we can mine
-        self.transact_and_mine(20, self.nodes[2])
-        check_estimates(self.nodes[1], self.fees_per_kb, 3)
+        for i in xrange(2):
+            print("Creating transactions and mining them with a block size that can't keep up")
+            # Create transactions and mine 10 small blocks with node 2, but create txs faster than we can mine
+            self.transact_and_mine(10, self.nodes[2])
+            check_estimates(self.nodes[1], self.fees_per_kb, 14)
 
-        print("Creating transactions and mining them at a block size that is just big enough")
-        # Generate transactions while mining 40 more blocks, this time with node1
-        # which mines blocks with capacity just above the rate that transactions are being created
-        self.transact_and_mine(40, self.nodes[1])
-        check_estimates(self.nodes[1], self.fees_per_kb, 2)
+            print("Creating transactions and mining them at a block size that is just big enough")
+            # Generate transactions while mining 10 more blocks, this time with node1
+            # which mines blocks with capacity just above the rate that transactions are being created
+            self.transact_and_mine(10, self.nodes[1])
+            check_estimates(self.nodes[1], self.fees_per_kb, 2)
 
         # Finish by mining a normal-sized block:
         while len(self.nodes[1].getrawmempool()) > 0:
diff --git a/src/main.h b/src/main.h
index eb61ff9570b14..347624c520d25 100644
--- a/src/main.h
+++ b/src/main.h
@@ -56,8 +56,6 @@ static const unsigned int DEFAULT_ANCESTOR_SIZE_LIMIT = 101;
 static const unsigned int DEFAULT_DESCENDANT_LIMIT = 25;
 /** Default for -limitdescendantsize, maximum kilobytes of in-mempool descendants */
 static const unsigned int DEFAULT_DESCENDANT_SIZE_LIMIT = 101;
-/** Default for -maxmempool, maximum megabytes of mempool memory usage */
-static const unsigned int DEFAULT_MAX_MEMPOOL_SIZE = 300;
 /** Default for -mempoolexpiry, expiration time for mempool transactions in hours */
 static const unsigned int DEFAULT_MEMPOOL_EXPIRY = 72;
 /** The maximum size of a blk?????.dat file (since 0.8) */
diff --git a/src/policy/fees.cpp b/src/policy/fees.cpp
index ffe31d19425cc..980ecf10dfc96 100644
--- a/src/policy/fees.cpp
+++ b/src/policy/fees.cpp
@@ -4,6 +4,7 @@
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include "policy/fees.h"
+#include "policy/policy.h"
 
 #include "amount.h"
 #include "primitives/transaction.h"
@@ -504,6 +505,33 @@ CFeeRate CBlockPolicyEstimator::estimateFee(int confTarget)
     return CFeeRate(median);
 }
 
+CFeeRate CBlockPolicyEstimator::estimateSmartFee(int confTarget, int *answerFoundAtTarget, const CTxMemPool& pool)
+{
+    if (answerFoundAtTarget)
+        *answerFoundAtTarget = confTarget;
+    // Return failure if trying to analyze a target we're not tracking
+    if (confTarget <= 0 || (unsigned int)confTarget > feeStats.GetMaxConfirms())
+        return CFeeRate(0);
+
+    double median = -1;
+    while (median < 0 && (unsigned int)confTarget <= feeStats.GetMaxConfirms()) {
+        median = feeStats.EstimateMedianVal(confTarget++, SUFFICIENT_FEETXS, MIN_SUCCESS_PCT, true, nBestSeenHeight);
+    }
+
+    if (answerFoundAtTarget)
+        *answerFoundAtTarget = confTarget - 1;
+
+    // If mempool is limiting txs , return at least the min fee from the mempool
+    CAmount minPoolFee = pool.GetMinFee(GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000).GetFeePerK();
+    if (minPoolFee > 0 && minPoolFee > median)
+        return CFeeRate(minPoolFee);
+
+    if (median < 0)
+        return CFeeRate(0);
+
+    return CFeeRate(median);
+}
+
 double CBlockPolicyEstimator::estimatePriority(int confTarget)
 {
     // Return failure if trying to analyze a target we're not tracking
@@ -513,6 +541,30 @@ double CBlockPolicyEstimator::estimatePriority(int confTarget)
     return priStats.EstimateMedianVal(confTarget, SUFFICIENT_PRITXS, MIN_SUCCESS_PCT, true, nBestSeenHeight);
 }
 
+double CBlockPolicyEstimator::estimateSmartPriority(int confTarget, int *answerFoundAtTarget, const CTxMemPool& pool)
+{
+    if (answerFoundAtTarget)
+        *answerFoundAtTarget = confTarget;
+    // Return failure if trying to analyze a target we're not tracking
+    if (confTarget <= 0 || (unsigned int)confTarget > priStats.GetMaxConfirms())
+        return -1;
+
+    // If mempool is limiting txs, no priority txs are allowed
+    CAmount minPoolFee = pool.GetMinFee(GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000).GetFeePerK();
+    if (minPoolFee > 0)
+        return INF_PRIORITY;
+
+    double median = -1;
+    while (median < 0 && (unsigned int)confTarget <= priStats.GetMaxConfirms()) {
+        median = priStats.EstimateMedianVal(confTarget++, SUFFICIENT_PRITXS, MIN_SUCCESS_PCT, true, nBestSeenHeight);
+    }
+
+    if (answerFoundAtTarget)
+        *answerFoundAtTarget = confTarget - 1;
+
+    return median;
+}
+
 void CBlockPolicyEstimator::Write(CAutoFile& fileout)
 {
     fileout << nBestSeenHeight;
diff --git a/src/policy/fees.h b/src/policy/fees.h
index 15577d128a3eb..7a293267d42d0 100644
--- a/src/policy/fees.h
+++ b/src/policy/fees.h
@@ -15,6 +15,7 @@
 class CAutoFile;
 class CFeeRate;
 class CTxMemPoolEntry;
+class CTxMemPool;
 
 /** \class CBlockPolicyEstimator
  * The BlockPolicyEstimator is used for estimating the fee or priority needed
@@ -182,8 +183,8 @@ static const unsigned int MAX_BLOCK_CONFIRMS = 25;
 /** Decay of .998 is a half-life of 346 blocks or about 2.4 days */
 static const double DEFAULT_DECAY = .998;
 
-/** Require greater than 85% of X fee transactions to be confirmed within Y blocks for X to be big enough */
-static const double MIN_SUCCESS_PCT = .85;
+/** Require greater than 95% of X fee transactions to be confirmed within Y blocks for X to be big enough */
+static const double MIN_SUCCESS_PCT = .95;
 static const double UNLIKELY_PCT = .5;
 
 /** Require an avg of 1 tx in the combined fee bucket per block to have stat significance */
@@ -242,9 +243,21 @@ class CBlockPolicyEstimator
     /** Return a fee estimate */
     CFeeRate estimateFee(int confTarget);
 
+    /** Estimate fee rate needed to get be included in a block within
+     *  confTarget blocks. If no answer can be given at confTarget, return an
+     *  estimate at the lowest target where one can be given.
+     */
+    CFeeRate estimateSmartFee(int confTarget, int *answerFoundAtTarget, const CTxMemPool& pool);
+
     /** Return a priority estimate */
     double estimatePriority(int confTarget);
 
+    /** Estimate priority needed to get be included in a block within
+     *  confTarget blocks. If no answer can be given at confTarget, return an
+     *  estimate at the lowest target where one can be given.
+     */
+    double estimateSmartPriority(int confTarget, int *answerFoundAtTarget, const CTxMemPool& pool);
+
     /** Write estimation data to a file */
     void Write(CAutoFile& fileout);
 
diff --git a/src/policy/policy.h b/src/policy/policy.h
index f269e8d4762e4..c8d2c1a924df1 100644
--- a/src/policy/policy.h
+++ b/src/policy/policy.h
@@ -25,6 +25,8 @@ static const unsigned int MAX_STANDARD_TX_SIZE = 100000;
 static const unsigned int MAX_P2SH_SIGOPS = 15;
 /** The maximum number of sigops we're willing to relay/mine in a single tx */
 static const unsigned int MAX_STANDARD_TX_SIGOPS = MAX_BLOCK_SIGOPS/5;
+/** Default for -maxmempool, maximum megabytes of mempool memory usage */
+static const unsigned int DEFAULT_MAX_MEMPOOL_SIZE = 300;
 /**
  * Standard script verification flags that standard transactions will comply
  * with. However scripts violating these flags may still be present in valid
diff --git a/src/qt/coincontroldialog.cpp b/src/qt/coincontroldialog.cpp
index 81b2597c3b0a3..cbc41f3416ef7 100644
--- a/src/qt/coincontroldialog.cpp
+++ b/src/qt/coincontroldialog.cpp
@@ -538,7 +538,7 @@ void CoinControlDialog::updateLabels(WalletModel *model, QDialog* dialog)
         nBytes = nBytesInputs + ((CoinControlDialog::payAmounts.size() > 0 ? CoinControlDialog::payAmounts.size() + 1 : 2) * 34) + 10; // always assume +1 output for change here
 
         // Priority
-        double mempoolEstimatePriority = mempool.estimatePriority(nTxConfirmTarget);
+        double mempoolEstimatePriority = mempool.estimateSmartPriority(nTxConfirmTarget);
         dPriority = dPriorityInputs / (nBytes - nBytesInputs + (nQuantityUncompressed * 29)); // 29 = 180 - 151 (uncompressed public keys are over the limit. max 151 bytes of the input are ignored for priority)
         sPriorityLabel = CoinControlDialog::getPriorityLabel(dPriority, mempoolEstimatePriority);
 
@@ -550,10 +550,8 @@ void CoinControlDialog::updateLabels(WalletModel *model, QDialog* dialog)
         // Fee
         nPayFee = CWallet::GetMinimumFee(nBytes, nTxConfirmTarget, mempool);
 
-        // Allow free?
-        double dPriorityNeeded = mempoolEstimatePriority;
-        if (dPriorityNeeded <= 0)
-            dPriorityNeeded = AllowFreeThreshold(); // not enough data, back to hard-coded
+        // Allow free? (require at least hard-coded threshold and default to that if no estimate)
+        double dPriorityNeeded = std::max(mempoolEstimatePriority, AllowFreeThreshold());
         fAllowFree = (dPriority >= dPriorityNeeded);
 
         if (fSendFreeTransactions)
@@ -649,8 +647,9 @@ void CoinControlDialog::updateLabels(WalletModel *model, QDialog* dialog)
     double dFeeVary;
     if (payTxFee.GetFeePerK() > 0)
         dFeeVary = (double)std::max(CWallet::GetRequiredFee(1000), payTxFee.GetFeePerK()) / 1000;
-    else
-        dFeeVary = (double)std::max(CWallet::GetRequiredFee(1000), mempool.estimateFee(nTxConfirmTarget).GetFeePerK()) / 1000;
+    else {
+        dFeeVary = (double)std::max(CWallet::GetRequiredFee(1000), mempool.estimateSmartFee(nTxConfirmTarget).GetFeePerK()) / 1000;
+    }
     QString toolTip4 = tr("Can vary +/- %1 satoshi(s) per input.").arg(dFeeVary);
 
     l3->setToolTip(toolTip4);
@@ -686,7 +685,7 @@ void CoinControlDialog::updateView()
     QFlags<Qt::ItemFlag> flgTristate = Qt::ItemIsSelectable | Qt::ItemIsEnabled | Qt::ItemIsUserCheckable | Qt::ItemIsTristate;
 
     int nDisplayUnit = model->getOptionsModel()->getDisplayUnit();
-    double mempoolEstimatePriority = mempool.estimatePriority(nTxConfirmTarget);
+    double mempoolEstimatePriority = mempool.estimateSmartPriority(nTxConfirmTarget);
 
     std::map<QString, std::vector<COutput> > mapCoins;
     model->listCoins(mapCoins);
diff --git a/src/qt/sendcoinsdialog.cpp b/src/qt/sendcoinsdialog.cpp
index 4b030fdaa07ee..7b714be5b1cb6 100644
--- a/src/qt/sendcoinsdialog.cpp
+++ b/src/qt/sendcoinsdialog.cpp
@@ -633,7 +633,8 @@ void SendCoinsDialog::updateSmartFeeLabel()
         return;
 
     int nBlocksToConfirm = defaultConfirmTarget - ui->sliderSmartFee->value();
-    CFeeRate feeRate = mempool.estimateFee(nBlocksToConfirm);
+    int estimateFoundAtBlocks = nBlocksToConfirm;
+    CFeeRate feeRate = mempool.estimateSmartFee(nBlocksToConfirm, &estimateFoundAtBlocks);
     if (feeRate <= CFeeRate(0)) // not enough data => minfee
     {
         ui->labelSmartFee->setText(BitcoinUnits::formatWithUnit(model->getOptionsModel()->getDisplayUnit(), CWallet::GetRequiredFee(1000)) + "/kB");
@@ -644,7 +645,7 @@ void SendCoinsDialog::updateSmartFeeLabel()
     {
         ui->labelSmartFee->setText(BitcoinUnits::formatWithUnit(model->getOptionsModel()->getDisplayUnit(), feeRate.GetFeePerK()) + "/kB");
         ui->labelSmartFee2->hide();
-        ui->labelFeeEstimation->setText(tr("Estimated to begin confirmation within %n block(s).", "", nBlocksToConfirm));
+        ui->labelFeeEstimation->setText(tr("Estimated to begin confirmation within %n block(s).", "", estimateFoundAtBlocks));
     }
 
     updateFeeMinimizedLabel();
diff --git a/src/rpcblockchain.cpp b/src/rpcblockchain.cpp
index 012370ed10995..c80838e1f1d59 100644
--- a/src/rpcblockchain.cpp
+++ b/src/rpcblockchain.cpp
@@ -10,6 +10,7 @@
 #include "coins.h"
 #include "consensus/validation.h"
 #include "main.h"
+#include "policy/policy.h"
 #include "primitives/transaction.h"
 #include "rpcserver.h"
 #include "streams.h"
diff --git a/src/rpcclient.cpp b/src/rpcclient.cpp
index 343b6234d4dd7..cab5819017e9b 100644
--- a/src/rpcclient.cpp
+++ b/src/rpcclient.cpp
@@ -96,6 +96,8 @@ static const CRPCConvertParam vRPCConvertParams[] =
     { "getrawmempool", 0 },
     { "estimatefee", 0 },
     { "estimatepriority", 0 },
+    { "estimatesmartfee", 0 },
+    { "estimatesmartpriority", 0 },
     { "prioritisetransaction", 1 },
     { "prioritisetransaction", 2 },
     { "setban", 2 },
diff --git a/src/rpcmining.cpp b/src/rpcmining.cpp
index 3fd07fc374952..19b031b86059d 100644
--- a/src/rpcmining.cpp
+++ b/src/rpcmining.cpp
@@ -726,3 +726,75 @@ UniValue estimatepriority(const UniValue& params, bool fHelp)
 
     return mempool.estimatePriority(nBlocks);
 }
+
+UniValue estimatesmartfee(const UniValue& params, bool fHelp)
+{
+    if (fHelp || params.size() != 1)
+        throw runtime_error(
+            "estimatesmartfee nblocks\n"
+            "\nWARNING: This interface is unstable and may disappear or change!\n"
+            "\nEstimates the approximate fee per kilobyte needed for a transaction to begin\n"
+            "confirmation within nblocks blocks if possible and return the number of blocks\n"
+            "for which the estimate is valid.\n"
+            "\nArguments:\n"
+            "1. nblocks     (numeric)\n"
+            "\nResult:\n"
+            "{\n"
+            "  \"feerate\" : x.x,     (numeric) estimate fee-per-kilobyte (in BTC)\n"
+            "  \"blocks\" : n         (numeric) block number where estimate was found\n"
+            "}\n"
+            "\n"
+            "A negative value is returned if not enough transactions and blocks\n"
+            "have been observed to make an estimate for any number of blocks.\n"
+            "However it will not return a value below the mempool reject fee.\n"
+            "\nExample:\n"
+            + HelpExampleCli("estimatesmartfee", "6")
+            );
+
+    RPCTypeCheck(params, boost::assign::list_of(UniValue::VNUM));
+
+    int nBlocks = params[0].get_int();
+
+    UniValue result(UniValue::VOBJ);
+    int answerFound;
+    CFeeRate feeRate = mempool.estimateSmartFee(nBlocks, &answerFound);
+    result.push_back(Pair("feerate", feeRate == CFeeRate(0) ? -1.0 : ValueFromAmount(feeRate.GetFeePerK())));
+    result.push_back(Pair("blocks", answerFound));
+    return result;
+}
+
+UniValue estimatesmartpriority(const UniValue& params, bool fHelp)
+{
+    if (fHelp || params.size() != 1)
+        throw runtime_error(
+            "estimatesmartpriority nblocks\n"
+            "\nWARNING: This interface is unstable and may disappear or change!\n"
+            "\nEstimates the approximate priority a zero-fee transaction needs to begin\n"
+            "confirmation within nblocks blocks if possible and return the number of blocks\n"
+            "for which the estimate is valid.\n"
+            "\nArguments:\n"
+            "1. nblocks     (numeric)\n"
+            "\nResult:\n"
+            "{\n"
+            "  \"priority\" : x.x,    (numeric) estimated priority\n"
+            "  \"blocks\" : n         (numeric) block number where estimate was found\n"
+            "}\n"
+            "\n"
+            "A negative value is returned if not enough transactions and blocks\n"
+            "have been observed to make an estimate for any number of blocks.\n"
+            "However if the mempool reject fee is set it will return 1e9 * MAX_MONEY.\n"
+            "\nExample:\n"
+            + HelpExampleCli("estimatesmartpriority", "6")
+            );
+
+    RPCTypeCheck(params, boost::assign::list_of(UniValue::VNUM));
+
+    int nBlocks = params[0].get_int();
+
+    UniValue result(UniValue::VOBJ);
+    int answerFound;
+    double priority = mempool.estimateSmartPriority(nBlocks, &answerFound);
+    result.push_back(Pair("priority", priority));
+    result.push_back(Pair("blocks", answerFound));
+    return result;
+}
diff --git a/src/rpcserver.cpp b/src/rpcserver.cpp
index 8bda5a037360c..83d2c2d5037fc 100644
--- a/src/rpcserver.cpp
+++ b/src/rpcserver.cpp
@@ -319,6 +319,8 @@ static const CRPCCommand vRPCCommands[] =
     { "util",               "verifymessage",          &verifymessage,          true  },
     { "util",               "estimatefee",            &estimatefee,            true  },
     { "util",               "estimatepriority",       &estimatepriority,       true  },
+    { "util",               "estimatesmartfee",       &estimatesmartfee,       true  },
+    { "util",               "estimatesmartpriority",  &estimatesmartpriority,  true  },
 
     /* Not shown in help */
     { "hidden",             "invalidateblock",        &invalidateblock,        true  },
diff --git a/src/rpcserver.h b/src/rpcserver.h
index dde8dfdcc3dbe..fc88f82be8b56 100644
--- a/src/rpcserver.h
+++ b/src/rpcserver.h
@@ -193,6 +193,8 @@ extern UniValue getblocktemplate(const UniValue& params, bool fHelp);
 extern UniValue submitblock(const UniValue& params, bool fHelp);
 extern UniValue estimatefee(const UniValue& params, bool fHelp);
 extern UniValue estimatepriority(const UniValue& params, bool fHelp);
+extern UniValue estimatesmartfee(const UniValue& params, bool fHelp);
+extern UniValue estimatesmartpriority(const UniValue& params, bool fHelp);
 
 extern UniValue getnewaddress(const UniValue& params, bool fHelp); // in rpcwallet.cpp
 extern UniValue getaccountaddress(const UniValue& params, bool fHelp);
diff --git a/src/test/policyestimator_tests.cpp b/src/test/policyestimator_tests.cpp
index c4f6660f6aed9..1315146f10976 100644
--- a/src/test/policyestimator_tests.cpp
+++ b/src/test/policyestimator_tests.cpp
@@ -84,11 +84,18 @@ BOOST_AUTO_TEST_CASE(BlockPolicyEstimates)
         block.clear();
         if (blocknum == 30) {
             // At this point we should need to combine 5 buckets to get enough data points
-            // So estimateFee(1) should fail and estimateFee(2) should return somewhere around
-            // 8*baserate
+            // So estimateFee(1,2,3) should fail and estimateFee(4) should return somewhere around
+            // 8*baserate.  estimateFee(4) %'s are 100,100,100,100,90 = average 98%
             BOOST_CHECK(mpool.estimateFee(1) == CFeeRate(0));
-            BOOST_CHECK(mpool.estimateFee(2).GetFeePerK() < 8*baseRate.GetFeePerK() + deltaFee);
-            BOOST_CHECK(mpool.estimateFee(2).GetFeePerK() > 8*baseRate.GetFeePerK() - deltaFee);
+            BOOST_CHECK(mpool.estimateFee(2) == CFeeRate(0));
+            BOOST_CHECK(mpool.estimateFee(3) == CFeeRate(0));
+            BOOST_CHECK(mpool.estimateFee(4).GetFeePerK() < 8*baseRate.GetFeePerK() + deltaFee);
+            BOOST_CHECK(mpool.estimateFee(4).GetFeePerK() > 8*baseRate.GetFeePerK() - deltaFee);
+            int answerFound;
+            BOOST_CHECK(mpool.estimateSmartFee(1, &answerFound) == mpool.estimateFee(4) && answerFound == 4);
+            BOOST_CHECK(mpool.estimateSmartFee(3, &answerFound) == mpool.estimateFee(4) && answerFound == 4);
+            BOOST_CHECK(mpool.estimateSmartFee(4, &answerFound) == mpool.estimateFee(4) && answerFound == 4);
+            BOOST_CHECK(mpool.estimateSmartFee(8, &answerFound) == mpool.estimateFee(8) && answerFound == 8);
         }
     }
 
@@ -97,9 +104,9 @@ BOOST_AUTO_TEST_CASE(BlockPolicyEstimates)
     // Highest feerate is 10*baseRate and gets in all blocks,
     // second highest feerate is 9*baseRate and gets in 9/10 blocks = 90%,
     // third highest feerate is 8*base rate, and gets in 8/10 blocks = 80%,
-    // so estimateFee(1) should return 9*baseRate.
-    // Third highest feerate has 90% chance of being included by 2 blocks,
-    // so estimateFee(2) should return 8*baseRate etc...
+    // so estimateFee(1) should return 10*baseRate.
+    // Second highest feerate has 100% chance of being included by 2 blocks,
+    // so estimateFee(2) should return 9*baseRate etc...
     for (int i = 1; i < 10;i++) {
         origFeeEst.push_back(mpool.estimateFee(i).GetFeePerK());
         origPriEst.push_back(mpool.estimatePriority(i));
@@ -107,10 +114,11 @@ BOOST_AUTO_TEST_CASE(BlockPolicyEstimates)
             BOOST_CHECK(origFeeEst[i-1] <= origFeeEst[i-2]);
             BOOST_CHECK(origPriEst[i-1] <= origPriEst[i-2]);
         }
-        BOOST_CHECK(origFeeEst[i-1] < (10-i)*baseRate.GetFeePerK() + deltaFee);
-        BOOST_CHECK(origFeeEst[i-1] > (10-i)*baseRate.GetFeePerK() - deltaFee);
-        BOOST_CHECK(origPriEst[i-1] < pow(10,10-i) * basepri + deltaPri);
-        BOOST_CHECK(origPriEst[i-1] > pow(10,10-i) * basepri - deltaPri);
+        int mult = 11-i;
+        BOOST_CHECK(origFeeEst[i-1] < mult*baseRate.GetFeePerK() + deltaFee);
+        BOOST_CHECK(origFeeEst[i-1] > mult*baseRate.GetFeePerK() - deltaFee);
+        BOOST_CHECK(origPriEst[i-1] < pow(10,mult) * basepri + deltaPri);
+        BOOST_CHECK(origPriEst[i-1] > pow(10,mult) * basepri - deltaPri);
     }
 
     // Mine 50 more blocks with no transactions happening, estimates shouldn't change
@@ -140,9 +148,12 @@ BOOST_AUTO_TEST_CASE(BlockPolicyEstimates)
         mpool.removeForBlock(block, ++blocknum, dummyConflicted);
     }
 
+    int answerFound;
     for (int i = 1; i < 10;i++) {
-        BOOST_CHECK(mpool.estimateFee(i).GetFeePerK() > origFeeEst[i-1] - deltaFee);
-        BOOST_CHECK(mpool.estimatePriority(i) > origPriEst[i-1] - deltaPri);
+        BOOST_CHECK(mpool.estimateFee(i) == CFeeRate(0) || mpool.estimateFee(i).GetFeePerK() > origFeeEst[i-1] - deltaFee);
+        BOOST_CHECK(mpool.estimateSmartFee(i, &answerFound).GetFeePerK() > origFeeEst[answerFound-1] - deltaFee);
+        BOOST_CHECK(mpool.estimatePriority(i) == -1 || mpool.estimatePriority(i) > origPriEst[i-1] - deltaPri);
+        BOOST_CHECK(mpool.estimateSmartPriority(i, &answerFound) > origPriEst[answerFound-1] - deltaPri);
     }
 
     // Mine all those transactions
@@ -162,9 +173,9 @@ BOOST_AUTO_TEST_CASE(BlockPolicyEstimates)
         BOOST_CHECK(mpool.estimatePriority(i) > origPriEst[i-1] - deltaPri);
     }
 
-    // Mine 100 more blocks where everything is mined every block
-    // Estimates should be below original estimates (not possible for last estimate)
-    while (blocknum < 365) {
+    // Mine 200 more blocks where everything is mined every block
+    // Estimates should be below original estimates
+    while (blocknum < 465) {
         for (int j = 0; j < 10; j++) { // For each fee/pri multiple
             for (int k = 0; k < 5; k++) { // add 4 fee txs for every priority tx
                 tx.vin[0].prevout.n = 10000*blocknum+100*j+k;
@@ -178,10 +189,22 @@ BOOST_AUTO_TEST_CASE(BlockPolicyEstimates)
         mpool.removeForBlock(block, ++blocknum, dummyConflicted);
         block.clear();
     }
-    for (int i = 1; i < 9; i++) {
+    for (int i = 1; i < 10; i++) {
         BOOST_CHECK(mpool.estimateFee(i).GetFeePerK() < origFeeEst[i-1] - deltaFee);
         BOOST_CHECK(mpool.estimatePriority(i) < origPriEst[i-1] - deltaPri);
     }
+
+    // Test that if the mempool is limited, estimateSmartFee won't return a value below the mempool min fee
+    // and that estimateSmartPriority returns essentially an infinite value
+    mpool.addUnchecked(tx.GetHash(),  CTxMemPoolEntry(tx, feeV[0][5], GetTime(), priV[1][5], blocknum, mpool.HasNoInputsOf(tx)));
+    // evict that transaction which should set a mempool min fee of minRelayTxFee + feeV[0][5]
+    mpool.TrimToSize(1);
+    BOOST_CHECK(mpool.GetMinFee(1).GetFeePerK() > feeV[0][5]);
+    for (int i = 1; i < 10; i++) {
+        BOOST_CHECK(mpool.estimateSmartFee(i).GetFeePerK() >= mpool.estimateFee(i).GetFeePerK());
+        BOOST_CHECK(mpool.estimateSmartFee(i).GetFeePerK() >= mpool.GetMinFee(1).GetFeePerK());
+        BOOST_CHECK(mpool.estimateSmartPriority(i) == INF_PRIORITY);
+    }
 }
 
 BOOST_AUTO_TEST_SUITE_END()
diff --git a/src/txmempool.cpp b/src/txmempool.cpp
index a772e7adeaf94..ec7971c2f1cca 100644
--- a/src/txmempool.cpp
+++ b/src/txmempool.cpp
@@ -701,11 +701,21 @@ CFeeRate CTxMemPool::estimateFee(int nBlocks) const
     LOCK(cs);
     return minerPolicyEstimator->estimateFee(nBlocks);
 }
+CFeeRate CTxMemPool::estimateSmartFee(int nBlocks, int *answerFoundAtBlocks) const
+{
+    LOCK(cs);
+    return minerPolicyEstimator->estimateSmartFee(nBlocks, answerFoundAtBlocks, *this);
+}
 double CTxMemPool::estimatePriority(int nBlocks) const
 {
     LOCK(cs);
     return minerPolicyEstimator->estimatePriority(nBlocks);
 }
+double CTxMemPool::estimateSmartPriority(int nBlocks, int *answerFoundAtBlocks) const
+{
+    LOCK(cs);
+    return minerPolicyEstimator->estimateSmartPriority(nBlocks, answerFoundAtBlocks, *this);
+}
 
 bool
 CTxMemPool::WriteFeeEstimates(CAutoFile& fileout) const
diff --git a/src/txmempool.h b/src/txmempool.h
index 7b5843a8d0d0f..5d8231fb778d4 100644
--- a/src/txmempool.h
+++ b/src/txmempool.h
@@ -454,9 +454,21 @@ class CTxMemPool
 
     bool lookup(uint256 hash, CTransaction& result) const;
 
+    /** Estimate fee rate needed to get into the next nBlocks
+     *  If no answer can be given at nBlocks, return an estimate
+     *  at the lowest number of blocks where one can be given
+     */
+    CFeeRate estimateSmartFee(int nBlocks, int *answerFoundAtBlocks = NULL) const;
+
     /** Estimate fee rate needed to get into the next nBlocks */
     CFeeRate estimateFee(int nBlocks) const;
 
+    /** Estimate priority needed to get into the next nBlocks
+     *  If no answer can be given at nBlocks, return an estimate
+     *  at the lowest number of blocks where one can be given
+     */
+    double estimateSmartPriority(int nBlocks, int *answerFoundAtBlocks = NULL) const;
+
     /** Estimate priority needed to get into the next nBlocks */
     double estimatePriority(int nBlocks) const;
     
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index 1b152f4192a3e..c5246d909e302 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -2010,13 +2010,9 @@ bool CWallet::CreateTransaction(const vector<CRecipient>& vecSend, CWalletTx& wt
                 if (fSendFreeTransactions && nBytes <= MAX_FREE_TRANSACTION_CREATE_SIZE)
                 {
                     // Not enough fee: enough priority?
-                    double dPriorityNeeded = mempool.estimatePriority(nTxConfirmTarget);
-                    // Not enough mempool history to estimate: use hard-coded AllowFree.
-                    if (dPriorityNeeded <= 0 && AllowFree(dPriority))
-                        break;
-
-                    // Small enough, and priority high enough, to send for free
-                    if (dPriorityNeeded > 0 && dPriority >= dPriorityNeeded)
+                    double dPriorityNeeded = mempool.estimateSmartPriority(nTxConfirmTarget);
+                    // Require at least hard-coded AllowFree.
+                    if (dPriority >= dPriorityNeeded && AllowFree(dPriority))
                         break;
                 }
 
@@ -2120,12 +2116,14 @@ CAmount CWallet::GetMinimumFee(unsigned int nTxBytes, unsigned int nConfirmTarge
     if (fPayAtLeastCustomFee && nFeeNeeded > 0 && nFeeNeeded < payTxFee.GetFeePerK())
         nFeeNeeded = payTxFee.GetFeePerK();
     // User didn't set: use -txconfirmtarget to estimate...
-    if (nFeeNeeded == 0)
-        nFeeNeeded = pool.estimateFee(nConfirmTarget).GetFee(nTxBytes);
-    // ... unless we don't have enough mempool data, in which case fall
-    // back to the required fee
-    if (nFeeNeeded == 0)
-        nFeeNeeded = GetRequiredFee(nTxBytes);
+    if (nFeeNeeded == 0) {
+        int estimateFoundTarget = nConfirmTarget;
+        nFeeNeeded = pool.estimateSmartFee(nConfirmTarget, &estimateFoundTarget).GetFee(nTxBytes);
+        // ... unless we don't have enough mempool data for our desired target
+        // so we make sure we're paying at least minTxFee
+        if (nFeeNeeded == 0 || (unsigned int)estimateFoundTarget > nConfirmTarget)
+            nFeeNeeded = std::max(nFeeNeeded, GetRequiredFee(nTxBytes));
+    }
     // prevent user from paying a non-sense fee (like 1 satoshi): 0 < fee < minRelayFee
     if (nFeeNeeded < ::minRelayTxFee.GetFee(nTxBytes))
         nFeeNeeded = ::minRelayTxFee.GetFee(nTxBytes);