diff --git a/bot-manager.js b/bot-manager.js
index a32a40a..ec78c6f 100644
--- a/bot-manager.js
+++ b/bot-manager.js
@@ -9,7 +9,6 @@ var BOT_DEFAULT_CHANGE_DIRECTION_PROBABILITY = 0.01;
 var BotManager = function (options) {
   this.worldWidth = options.worldWidth;
   this.worldHeight = options.worldHeight;
-  this.botDiameter = options.botDiameter || BOT_DEFAULT_DIAMETER;
   if (options.botMoveSpeed == null) {
     this.botMoveSpeed = BOT_DEFAULT_SPEED;
   } else {
@@ -17,6 +16,7 @@ var BotManager = function (options) {
   }
   this.botMass = options.botMass || BOT_DEFAULT_MASS;
   this.botChangeDirectionProbability = options.botChangeDirectionProbability || BOT_DEFAULT_CHANGE_DIRECTION_PROBABILITY;
+  this.botDefaultDiameter = options.botDefaultDiameter || BOT_DEFAULT_DIAMETER;
 
   this.botMoves = [
     {u: 1},
@@ -39,7 +39,7 @@ BotManager.prototype.addBot = function (options) {
   if (!options) {
     options = {};
   }
-  var diameter = this.botDiameter;
+  var diameter = options.diam || this.botDefaultDiameter;
   var radius = Math.round(diameter / 2);
   var botId = uuid.v4();
 
@@ -51,8 +51,7 @@ BotManager.prototype.addBot = function (options) {
     score: options.score || 0,
     speed: options.speed == null ? this.botMoveSpeed : options.speed,
     mass: options.mass || this.botMass,
-    width: diameter,
-    height: diameter,
+    diam: diameter,
     changeDirProb: this.botChangeDirectionProbability,
     op: {}
   };
diff --git a/cell.js b/cell.js
index 6e08003..9f38617 100644
--- a/cell.js
+++ b/cell.js
@@ -67,7 +67,7 @@ var CellController = function (options, util) {
   this.botManager = new BotManager({
     worldWidth: config.WORLD_WIDTH,
     worldHeight: config.WORLD_HEIGHT,
-    botDiameter: config.BOT_DIAMETER,
+    botDefaultDiameter: config.BOT_DEFAULT_DIAMETER,
     botMoveSpeed: config.BOT_MOVE_SPEED,
     botMass: config.BOT_MASS,
     botChangeDirectionProbability: config.BOT_CHANGE_DIRECTION_PROBABILITY
@@ -194,7 +194,7 @@ CellController.prototype.generateBotOps = function (playerIds, players, coins) {
     // states are not saved unless they are grouped with one or more internal states from the current cell.
     // See util.groupStates() method near the bottom of this file for details.
     if (player.subtype == 'bot' && !player.external) {
-      var radius = Math.round(player.width / 2);
+      var radius = Math.round(player.diam / 2);
       var isBotOnEdge = player.x <= radius || player.x >= config.WORLD_WIDTH - radius ||
         player.y <= radius || player.y >= config.WORLD_HEIGHT - radius;
 
@@ -210,23 +210,22 @@ CellController.prototype.generateBotOps = function (playerIds, players, coins) {
 };
 
 CellController.prototype.keepPlayerOnGrid = function (player) {
-  var halfWidth = Math.round(player.width / 2);
-  var halfHeight = Math.round(player.height / 2);
+  var radius = Math.round(player.diam / 2);
 
-  var leftX = player.x - halfWidth;
-  var rightX = player.x + halfWidth;
-  var topY = player.y - halfHeight;
-  var bottomY = player.y + halfHeight;
+  var leftX = player.x - radius;
+  var rightX = player.x + radius;
+  var topY = player.y - radius;
+  var bottomY = player.y + radius;
 
   if (leftX < 0) {
-    player.x = halfWidth;
+    player.x = radius;
   } else if (rightX > config.WORLD_WIDTH) {
-    player.x = config.WORLD_WIDTH - halfWidth;
+    player.x = config.WORLD_WIDTH - radius;
   }
   if (topY < 0) {
-    player.y = halfHeight;
+    player.y = radius;
   } else if (bottomY > config.WORLD_HEIGHT) {
-    player.y = config.WORLD_HEIGHT - halfHeight;
+    player.y = config.WORLD_HEIGHT - radius;
   }
 };
 
@@ -353,7 +352,7 @@ CellController.prototype.findPlayerOverlaps = function (playerIds, players, coin
 };
 
 CellController.prototype.generateHitArea = function (target) {
-  var targetRadius = target.r || Math.round(target.width / 2);
+  var targetRadius = target.r || Math.round(target.diam / 2);
   return {
     target: target,
     minX: target.x - targetRadius,
@@ -364,8 +363,8 @@ CellController.prototype.generateHitArea = function (target) {
 };
 
 CellController.prototype.testCircleCollision = function (a, b) {
-  var radiusA = a.r || Math.round(a.width / 2);
-  var radiusB = b.r || Math.round(b.width / 2);
+  var radiusA = a.r || Math.round(a.diam / 2);
+  var radiusB = b.r || Math.round(b.diam / 2);
 
   var circleA = new SAT.Circle(new SAT.Vector(a.x, a.y), radiusA);
   var circleB = new SAT.Circle(new SAT.Vector(b.x, b.y), radiusB);
diff --git a/config.js b/config.js
index 9c104d8..5065781 100644
--- a/config.js
+++ b/config.js
@@ -47,7 +47,7 @@ module.exports = {
   BOT_COUNT: 10,
   BOT_MOVE_SPEED: 5,
   BOT_MASS: 10,
-  BOT_DIAMETER: 45,
+  BOT_DEFAULT_DIAMETER: 45,
   BOT_CHANGE_DIRECTION_PROBABILITY: 0.01,
 
   COIN_UPDATE_INTERVAL: 1000,
diff --git a/public/index.html b/public/index.html
index dcea401..532ffbb 100644
--- a/public/index.html
+++ b/public/index.html
@@ -92,7 +92,7 @@
           WORLD_ROWS = data.rows;
           WORLD_CELL_WIDTH = data.cellWidth;
           WORLD_CELL_HEIGHT = data.cellHeight;
-          WORLD_CELL_OVERLAP_DISTANCE = data.cellOverlapDistance
+          WORLD_CELL_OVERLAP_DISTANCE = data.cellOverlapDistance;
           SERVER_WORKER_ID = data.serverWorkerId;
           ENVIRONMENT = data.environment;
 
@@ -251,8 +251,9 @@
           user.score = userData.score;
           user.sprite = sprite;
 
-          user.width = user.sprite.width;
-          user.height = user.sprite.height;
+          user.sprite.width = Math.round(userData.diam * 0.75);
+          user.sprite.height = userData.diam;
+          user.diam = user.sprite.width;
 
           moveUser(userData.id, userData.x, userData.y);
 
diff --git a/worker.js b/worker.js
index 379efe7..634c8d5 100644
--- a/worker.js
+++ b/worker.js
@@ -715,8 +715,7 @@ module.exports.run = function (worker) {
         name: playerOptions.name,
         x: startingPos.x,
         y: startingPos.y,
-        width: PLAYER_DIAMETER,
-        height: PLAYER_DIAMETER,
+        diam: PLAYER_DIAMETER,
         mass: PLAYER_MASS,
         score: 0
       };