Look at the largest dimension (width or height)
- 1 zoom level: 1 to 256
- 2 zoom levels: 257 to 513
- 3 zoom levels: 514 to 1027
- 4 zoom levels: 1028 to 2055
- 5 zoom levels: 2056 to 4111
- 6 zoom levels: 4112 to 8223
- ...
- n zoom levels:
(2^(n-2)) * (256 + 1)to(2^(n-1) * (256 + 1)) - 1(except when n = 1, in which case the lower bound is just 1)