# Level Horizon Calibration
You can use Level Horizon Calibration to compensate for small misalignments in controller orientation and to level the horizon in the QGroundControl flight view (blue on top and green on bottom).
Performing this calibration step is only recommended if the autopilot's orientation is visibly misaligned with the specified orientation, or if there is a constant drift during flight in not position-controlled flight modes.
# Performing the Calibration
To level the horizon:
Start QGroundControl and connect the vehicle.
Select the Gear icon (Vehicle Setup) in the top toolbar and then Sensors in the sidebar.
Click the Level Horizon button.
You should already have set the Autopilot Orientation. If not, you can also set it here.
Place the vehicle in its level flight orientation on a level surface:
- For planes this is the position during level flight (planes tend to have their wings slightly pitched up!)
- For copters this is the hover position.
Press OK to start the calibration process.
Wait until the calibration process is finished.
Check that the artificial horizon displayed in the flight view has the indicator in the middle when the vehicle is placed on a level surface.
# Further Information
- Advanced Orientation Tuning (advanced users only).
- QGroundControl User Guide > Sensors (opens new window)
- PX4 Setup Video "Gyroscope" - @1m14s (opens new window) (Youtube)