diff --git a/src/jexer/backend/ECMA48Terminal.java b/src/jexer/backend/ECMA48Terminal.java
index 4d04923..2b438ef 100644
--- a/src/jexer/backend/ECMA48Terminal.java
+++ b/src/jexer/backend/ECMA48Terminal.java
@@ -336,6 +336,21 @@ public class ECMA48Terminal extends LogicalScreen
      */
     private boolean hasSynchronizedOutput = false;
 
+    /**
+     * The time we last flushed output in flushPhysical().
+     */
+    private long lastFlushTime;
+
+    /**
+     * The bytes being written in this second.
+     */
+    private int bytesPerSecond;
+
+    /**
+     * The bytes per second for the last second.
+     */
+    private int lastBytesPerSecond;
+
     /**
      * The terminal's input.  If an InputStream is not specified in the
      * constructor, then this InputStreamReader will be bound to System.in
@@ -882,6 +897,15 @@ public class ECMA48Terminal extends LogicalScreen
                 }
             }
             output.flush();
+
+            long now = System.currentTimeMillis();
+            if ((int) (now / 1000) == (int) (lastFlushTime / 1000)) {
+                bytesPerSecond += sb.length();
+            } else {
+                lastBytesPerSecond = sb.length();
+                bytesPerSecond = 0;
+            }
+            lastFlushTime = now;
         }
     }
 
@@ -1296,6 +1320,15 @@ public class ECMA48Terminal extends LogicalScreen
     // ECMA48Terminal ---------------------------------------------------------
     // ------------------------------------------------------------------------
 
+    /**
+     * Get the bytes per second from the last second.
+     *
+     * @return the bytes per second
+     */
+    public int getBytesPerSecond() {
+        return lastBytesPerSecond;
+    }
+
     /**
      * Get the width of a character cell in pixels.
      *
diff --git a/src/jexer/demos/DemoApplication.java b/src/jexer/demos/DemoApplication.java
index 20c1628..f8e0b16 100644
--- a/src/jexer/demos/DemoApplication.java
+++ b/src/jexer/demos/DemoApplication.java
@@ -45,6 +45,7 @@ import jexer.TEditorWindow;
 import jexer.TWidget;
 import jexer.TWindow;
 import jexer.bits.BorderStyle;
+import jexer.backend.ECMA48Terminal;
 import jexer.event.TMenuEvent;
 import jexer.menu.TMenu;
 import jexer.menu.TMenuItem;
@@ -302,7 +303,27 @@ public class DemoApplication extends TApplication {
      */
     @Override
     protected void onPreDraw() {
-        menuTrayText = String.format("FPS %d", getFramesPerSecond());
+        if (getScreen() instanceof ECMA48Terminal) {
+            ECMA48Terminal terminal = (ECMA48Terminal) getScreen();
+            int bytes = terminal.getBytesPerSecond();
+            String bps = "";
+            if (bytes > 1024 * 1024 * 1024) {
+                bps = String.format("%4.2f GB/s",
+                    ((double) bytes / (1024 * 1024 * 1024)));
+            } else if (bytes > 1024 * 1024) {
+                bps = String.format("%4.2f MB/s",
+                    ((double) bytes / (1024 * 1024)));
+            } else if (bytes > 1024) {
+                bps = String.format("%4.2f KB/s",
+                    ((double) bytes / 1024));
+            } else {
+                bps = String.format("%d bytes/s", bytes);
+            }
+            menuTrayText = String.format("%s FPS %d", bps,
+                getFramesPerSecond());
+        } else {
+            menuTrayText = String.format("FPS %d", getFramesPerSecond());
+        }
     }
 
     // ------------------------------------------------------------------------