Calibrating a Power Meter is easily done using either the manufacturer’s app or your cycling computer. A few things to check/do before calibrating:
1- Ensure that your firmware is up to date.
2- If this is a brand new power meter, do a few rides, and include a few sprints. A brand new power meter may not be accurate on the first ride
Prior to calibrating, spin the cranks to wake up the power meter, ensure that you are not clipped in and that the cranks are at 90º (vertical). A Zero Offset is the point at which the power meter interprets to have zero weight applied to it. Your power meter may report a value, or may simply say “successful”. You will need to check your user manual to learn to interpret any values specific to your power meter. User manuals can be found online if you can’t locate the one that came with your device.
Using a Wahoo Elemnt computer
Instructions are found here: How do I Calibrate a Power Meter with the ELEMNT/BOLT/ROAM?
Using the manufacturer’s app
Pair the power meter to the manufacturer's app and follow the instructions on the screen. Once the calibration is complete, close down the app and connect your power meter to the SYSTM app.