diff --git a/src/portcontrol.cpp b/src/portcontrol.cpp
--- a/src/portcontrol.cpp
+++ b/src/portcontrol.cpp
@@ -514,6 +514,27 @@ void PortControl::openPort()
     }
 }
 
+unsigned PortControl::maxBitRate() const
+{
+    float baud = serialPort->baudRate();
+    float dataBits = serialPort->dataBits();
+    float parityBits = serialPort->parity() == QSerialPort::NoParity ? 0 : 1;
+
+    float stopBits;
+    if (serialPort->stopBits() == QSerialPort::OneAndHalfStop)
+    {
+        stopBits = 1.5;
+    }
+    else
+    {
+        stopBits = serialPort->stopBits();
+    }
+
+    float frame_size = 1 /* start bit */ + dataBits + parityBits + stopBits;
+
+    return float(baud) / frame_size;
+}
+
 void PortControl::saveSettings(QSettings* settings)
 {
     settings->beginGroup(SettingGroup_Port);