# Calibrating the Tool

The calibration value used for the tool is calculated from the torque readings read from the controller, and the torque reference transducer through the equation below:

New calibration value = Old calibration value × Mean (Reference values / Controller values)

1. On the home view, go to the Tool tab and select the tool to be calibrated. Then, go to the Calibration window.

2. Take note the old calibration value found in the Calibration value text box.

   If the calibration value is adjusted by more than 10%, a confirmation prompt is displayed as the change may significantly impact the accuracy and performance of the system.

3. Make at least three tightenings and use the torque values read from the controller and the reference transducer (ACTA or similar) for calculating the mean torque values.

4. Calculate the new calibration value using the New calibration value equation.

5. Store the new calibration value in the tool memory by entering the calculated value in the Calibration value text box and selecting Apply.

After calibration is completed, perform a tightening to verify that the new values are correct.