diff --git a/src/NzbDrone.Common.Test/ExtensionTests/Int64ExtensionFixture.cs b/src/NzbDrone.Common.Test/ExtensionTests/Int64ExtensionFixture.cs
index 40d78ed09..76e28f3f7 100644
--- a/src/NzbDrone.Common.Test/ExtensionTests/Int64ExtensionFixture.cs
+++ b/src/NzbDrone.Common.Test/ExtensionTests/Int64ExtensionFixture.cs
@@ -8,13 +8,15 @@ namespace NzbDrone.Common.Test.ExtensionTests
     public class Int64ExtensionFixture
     {
         [TestCase(0, "0 B")]
-        [TestCase(1000, "1.0 KB")]
-        [TestCase(1000000, "1.0 MB")]
-        [TestCase(377487360, "377.5 MB")]
-        [TestCase(1255864686, "1.3 GB")]
-        [TestCase(-1000000, "-1.0 MB")]
-        [TestCase(-377487360, "-377.5 MB")]
-        [TestCase(-1255864686, "-1.3 GB")]
+        [TestCase(1000, "1,000.0 B")]
+        [TestCase(1024, "1.0 KB")]
+        [TestCase(1000000, "976.6 KB")]
+        [TestCase(377487360, "360.0 MB")]
+        [TestCase(1255864686, "1.2 GB")]
+        [TestCase(-1024, "-1.0 KB")]
+        [TestCase(-1000000, "-976.6 KB")]
+        [TestCase(-377487360, "-360.0 MB")]
+        [TestCase(-1255864686, "-1.2 GB")]
         public void should_calculate_string_correctly(long bytes, string expected)
         {
             bytes.SizeSuffix().Should().Be(expected);
diff --git a/src/NzbDrone.Common/Extensions/Int64Extensions.cs b/src/NzbDrone.Common/Extensions/Int64Extensions.cs
index 43ec6c454..3da216ce9 100644
--- a/src/NzbDrone.Common/Extensions/Int64Extensions.cs
+++ b/src/NzbDrone.Common/Extensions/Int64Extensions.cs
@@ -9,7 +9,7 @@ namespace NzbDrone.Common.Extensions
 
         public static string SizeSuffix(this Int64 bytes)
         {
-            const int bytesInKb = 1000;
+            const int bytesInKb = 1024;
 
             if (bytes < 0) return "-" + SizeSuffix(-bytes);
             if (bytes == 0) return "0 B";
diff --git a/src/UI/Activity/Queue/TimeleftCell.js b/src/UI/Activity/Queue/TimeleftCell.js
index 561fc8068..766d9df2d 100644
--- a/src/UI/Activity/Queue/TimeleftCell.js
+++ b/src/UI/Activity/Queue/TimeleftCell.js
@@ -1,5 +1,4 @@
 var NzbDroneCell = require('../../Cells/NzbDroneCell');
-var fileSize = require('filesize');
 var moment = require('moment');
 var UiSettingsModel = require('../../Shared/UiSettingsModel');
 var FormatHelpers = require('../../Shared/FormatHelpers');
@@ -19,8 +18,8 @@ module.exports = NzbDroneCell.extend({
             }
 
             var timeleft = this.cellValue.get('timeleft');
-            var totalSize = fileSize(this.cellValue.get('size'), 1, false);
-            var remainingSize = fileSize(this.cellValue.get('sizeleft'), 1, false);
+            var totalSize = FormatHelpers.bytes(this.cellValue.get('size'), 2);
+            var remainingSize = FormatHelpers.bytes(this.cellValue.get('sizeleft'), 2);
 
             if (timeleft === undefined) {
                 this.$el.html('-');
diff --git a/src/UI/Settings/Quality/Definition/QualityDefinitionItemView.js b/src/UI/Settings/Quality/Definition/QualityDefinitionItemView.js
index d0b087d78..b663cf310 100644
--- a/src/UI/Settings/Quality/Definition/QualityDefinitionItemView.js
+++ b/src/UI/Settings/Quality/Definition/QualityDefinitionItemView.js
@@ -1,7 +1,7 @@
 var Marionette = require('marionette');
 var AsModelBoundView = require('../../../Mixins/AsModelBoundView');
-var fileSize = require('filesize');
 require('jquery-ui');
+var FormatHelpers = require('../../../Shared/FormatHelpers');
 
 var view = Marionette.ItemView.extend({
     template  : 'Settings/Quality/Definition/QualityDefinitionItemViewTemplate',
@@ -27,7 +27,6 @@ var view = Marionette.ItemView.extend({
 
     initialize : function(options) {
         this.profileCollection = options.profiles;
-        this.filesize = fileSize;
     },
 
     onRender : function() {
@@ -66,11 +65,10 @@ var view = Marionette.ItemView.extend({
     _changeSize : function() {
         var minSize = this.model.get('minSize') || this.slider.min;
         var maxSize = this.model.get('maxSize') || null;
-
         {
             var minBytes = minSize * 1024 * 1024;
-            var minThirty = fileSize(minBytes * 30, 1, false);
-            var minSixty = fileSize(minBytes * 60, 1, false);
+            var minThirty = FormatHelpers.bytes(minBytes * 30, 2);
+            var minSixty = FormatHelpers.bytes(minBytes * 60, 2);
 
             this.ui.thirtyMinuteMinSize.html(minThirty);
             this.ui.sixtyMinuteMinSize.html(minSixty);
@@ -82,8 +80,8 @@ var view = Marionette.ItemView.extend({
                 this.ui.sixtyMinuteMaxSize.html('Unlimited');
             } else {
                 var maxBytes = maxSize * 1024 * 1024;
-                var maxThirty = fileSize(maxBytes * 30, 1, false);
-                var maxSixty = fileSize(maxBytes * 60, 1, false);
+                var maxThirty = FormatHelpers.bytes(maxBytes * 30, 2);
+                var maxSixty = FormatHelpers.bytes(maxBytes * 60, 2);
 
                 this.ui.thirtyMinuteMaxSize.html(maxThirty);
                 this.ui.sixtyMinuteMaxSize.html(maxSixty);
diff --git a/src/UI/Shared/FormatHelpers.js b/src/UI/Shared/FormatHelpers.js
index 71f4faf8d..351501acd 100644
--- a/src/UI/Shared/FormatHelpers.js
+++ b/src/UI/Shared/FormatHelpers.js
@@ -3,16 +3,21 @@ var filesize = require('filesize');
 var UiSettings = require('./UiSettingsModel');
 
 module.exports = {
-    bytes : function(sourceSize) {
+    bytes : function(sourceSize, sourceRounding) {
         var size = Number(sourceSize);
+        var rounding = Number(sourceRounding);
 
         if (isNaN(size)) {
             return '';
         }
+        
+        if (isNaN(rounding)) {
+            rounding = 1;
+        }
 
         return filesize(size, {
             base  : 2,
-            round : 1
+            round : rounding
         });
     },