diff --git a/NAMESPACE b/NAMESPACE
index 22e314b7e..f8022f4bf 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -1,8 +1,8 @@
-export("%+%")
 export("%==%")
+export("%+%")
+export(stri_charcategories)
 export(stri_char_getcategoryid)
 export(stri_char_getpropertyid)
-export(stri_charcategories)
 export(stri_chartype)
 export(stri_dup)
 export(stri_encinfo)
@@ -12,6 +12,7 @@ export(stri_encset)
 export(stri_flatten)
 export(stri_info)
 export(stri_join)
+export(stri_length)
 export(stri_localeinfo)
 export(stri_localelist)
 export(stri_localeset)
@@ -20,8 +21,8 @@ export(stri_locate_first_class)
 export(stri_locate_last_class)
 export(stri_nfc)
 export(stri_nfd)
-export(stri_nfkc_casefold)
 export(stri_nfkc)
+export(stri_nfkc_casefold)
 export(stri_nfkd)
 export(stri_numbytes)
 export(stri_split)
diff --git a/R/length.R b/R/length.R
index 7bd85b3e9..2477e97bc 100644
--- a/R/length.R
+++ b/R/length.R
@@ -27,3 +27,13 @@ stri_numbytes <- function(str) {
    # prepare_arg done internally
    .Call("stri_numbytes", str, PACKAGE="stringi")
 }
+
+
+#' The number of characters in a string
+#' 
+#' @param str character vector
+#' @return integer vector giving the number of characters in each element of character vector
+#' @export
+stri_length <- function(str) {
+   .Call("stri_length", str, PACKAGE="stringi")
+}
diff --git a/src/length.cpp b/src/length.cpp
index 99b11df11..162678bc2 100644
--- a/src/length.cpp
+++ b/src/length.cpp
@@ -66,3 +66,28 @@ SEXP stri_numbytes(SEXP s)
    UNPROTECT(1);
    return ret;
 }
+
+SEXP stri_length(SEXP s)
+{
+    s = stri_prepare_arg_string(s);
+    int ns = LENGTH(s);
+    UChar32 c;
+    
+    SEXP ret;
+    PROTECT(ret = allocVector(INTSXP, ns));
+    
+    for (int k = 0; k < ns; k++) {
+        SEXP q = STRING_ELT(s, k);
+        if (q == NA_STRING)
+            INTEGER(ret)[k] = NA_INTEGER;
+        else {
+            int j = 0;      // number of code points
+            int nq = LENGTH(q);
+            for (int i = 0; i < nq; j++)
+                U8_NEXT(CHAR(q), i, nq, c);
+            INTEGER(ret)[k] = j;
+        }
+    }
+    UNPROTECT(1);
+    return ret;
+}
diff --git a/src/stringi.cpp b/src/stringi.cpp
index 2660f71dd..21dc73165 100644
--- a/src/stringi.cpp
+++ b/src/stringi.cpp
@@ -44,6 +44,7 @@ static const R_CallMethodDef cCallMethods[] = {
    {"stri_info",                       (DL_FUNC)&stri_info,                       0},
    {"stri_join",                       (DL_FUNC)&stri_join,                       1},
    {"stri_join2",                      (DL_FUNC)&stri_join2,                      2},
+   {"stri_length",                     (DL_FUNC)&stri_length,                     1},
    {"stri_localeinfo",                 (DL_FUNC)&stri_localeinfo,                 1},
    {"stri_localelist",                 (DL_FUNC)&stri_localelist,                 0},
    {"stri_localeset",                  (DL_FUNC)&stri_localeset,                  1},
diff --git a/src/stringi.h b/src/stringi.h
index 318dceed4..6244cef46 100644
--- a/src/stringi.h
+++ b/src/stringi.h
@@ -164,6 +164,7 @@ SEXP stri_char_getpropertyid(SEXP x);
 // length.cpp
 SEXP stri_numbytes(SEXP s);
 R_len_t stri__numbytes_max(SEXP s);
+SEXP stri_length(SEXP s);
 
 // wrap.cpp
 SEXP stri_wrap_greedy(SEXP count, SEXP width, SEXP spacecost);