You can swap from 17's to 20's without needing to recalibrate as long as the overall diameter is the same. The factory offers different sizes but doesn't need to recalibrate because the diameter is the same.
For example the base Tundra comes with 265/70R17s while my Limited comes with 275/55R20s. The overall diameter differs by 0.9% which is negligible. The smaller rim has a larger sidewall profile (70%) vs the larger rims low profile (55%) which gives similar diameters.
Just find a 20" tire with the same diameter (or close)as the stock 17s and you don't need to do anything.
Here is a tire size comparison chart where you can plug in different sizes.
