Power on your V5 Controller.
Use the arrow buttons to move the highlight over the Settings icon.
Press the A or down arrow button to select Settings.
Use the arrow buttons to move up or down to highlight the Calibrate option.
Then press the A button to select it.
Use your thumbs to tilt the joysticks on the V5 Controller as far as they can go. Then move them in a full circle of their full range of motion.
In this image, the left joystick has already been calibrated, and you can tell by the check mark. The right one still needs to be as shown by the clockwise circle of arrows.
You'll see this display when both joysticks have been calibrated.
Press the A button to set the calibration.
You'll see this display that asks you to accept the calibration.
If you want to accept it, press the A button.
If you want to calibrate your joysticks again, press the B button.