diff --git a/core/src/main/groovy/com/muwire/core/upload/ContentUploader.groovy b/core/src/main/groovy/com/muwire/core/upload/ContentUploader.groovy
index 05a287a9..a2457df2 100644
--- a/core/src/main/groovy/com/muwire/core/upload/ContentUploader.groovy
+++ b/core/src/main/groovy/com/muwire/core/upload/ContentUploader.groovy
@@ -62,11 +62,13 @@ class ContentUploader extends Uploader {
             mapped = channel.map(FileChannel.MapMode.READ_ONLY, range.start, range.end - range.start + 1)
             byte [] tmp = new byte[0x1 << 13]
             while(mapped.hasRemaining()) {
-                int start = mapped.position()
+                int read
                 synchronized(this) {
+                    int start = mapped.position()
                     mapped.get(tmp, 0, Math.min(tmp.length, mapped.remaining()))
+                    read = mapped.position() - start
+                    dataSinceLastRead += read
                 }
-                int read = mapped.position() - start
                 endpoint.getOutputStream().write(tmp, 0, read)
             }
         } finally {
diff --git a/core/src/main/groovy/com/muwire/core/upload/HashListUploader.groovy b/core/src/main/groovy/com/muwire/core/upload/HashListUploader.groovy
index 4be57da2..e344a29a 100644
--- a/core/src/main/groovy/com/muwire/core/upload/HashListUploader.groovy
+++ b/core/src/main/groovy/com/muwire/core/upload/HashListUploader.groovy
@@ -26,11 +26,13 @@ class HashListUploader extends Uploader {
 
         byte[]tmp = new byte[0x1 << 13]
         while(mapped.hasRemaining()) {
-            int start = mapped.position()
+            int read
             synchronized(this) {
+                int start = mapped.position()
                 mapped.get(tmp, 0, Math.min(tmp.length, mapped.remaining()))
+                read = mapped.position() - start
+                dataSinceLastRead += read
             }
-            int read = mapped.position() - start
             endpoint.getOutputStream().write(tmp, 0, read)
         }
         endpoint.getOutputStream().flush()
diff --git a/core/src/main/groovy/com/muwire/core/upload/Uploader.groovy b/core/src/main/groovy/com/muwire/core/upload/Uploader.groovy
index c065383a..559aaa44 100644
--- a/core/src/main/groovy/com/muwire/core/upload/Uploader.groovy
+++ b/core/src/main/groovy/com/muwire/core/upload/Uploader.groovy
@@ -11,7 +11,13 @@ import com.muwire.core.connection.Endpoint
 abstract class Uploader {
     protected final Endpoint endpoint
     protected ByteBuffer mapped
+    
+    private long lastSpeedRead
+    protected int dataSinceLastRead
 
+    private final ArrayList<Integer> speedArr = [0,0,0,0,0]
+    private int speedPos, speedAvg
+    
     Uploader(Endpoint endpoint) {
         this.endpoint = endpoint
     }
@@ -38,4 +44,34 @@ abstract class Uploader {
     abstract int getTotalPieces();
 
     abstract long getTotalSize();
+    
+    synchronized int speed() {
+        final long now = System.currentTimeMillis()
+        long interval = Math.max(1000, now - lastSpeedRead)
+        lastSpeedRead = now;
+        int currSpeed = (int) (dataSinceLastRead * 1000.0 / interval)
+        dataSinceLastRead = 0
+
+        // normalize to speedArr.size
+        currSpeed /= speedArr.size()
+
+        // compute new speedAvg and update speedArr
+        if ( speedArr[speedPos] > speedAvg ) {
+            speedAvg = 0
+        } else {
+            speedAvg -= speedArr[speedPos]
+        }
+        speedAvg += currSpeed
+        speedArr[speedPos] = currSpeed
+        // this might be necessary due to rounding errors
+        if (speedAvg < 0)
+            speedAvg = 0
+
+        // rolling index over the speedArr
+        speedPos++
+        if (speedPos >= speedArr.size())
+            speedPos=0
+
+        speedAvg
+    }
 }
diff --git a/gui/griffon-app/views/com/muwire/gui/MainFrameView.groovy b/gui/griffon-app/views/com/muwire/gui/MainFrameView.groovy
index 0093490a..0d0144cd 100644
--- a/gui/griffon-app/views/com/muwire/gui/MainFrameView.groovy
+++ b/gui/griffon-app/views/com/muwire/gui/MainFrameView.groovy
@@ -293,6 +293,10 @@ class MainFrameView {
                                             }
                                             String.format("%02d", percent) + "% ${totalSize} ($done/$pieces pcs)".toString()
                                         })
+                                        closureColumn(header : "Speed", type : String, read : { row ->
+                                            int speed = row.uploader.speed()
+                                            DataHelper.formatSize2Decimal(speed, false) + "B/sec"
+                                        })
                                     }
                                 }
                             }