The wheel dimensions are expressed in inches (28, 29 etc...), this is the size of the whole wheel including the tyre.
These dimensions each correspond to a diameter expressed in millimetres, the ETRTO code.
Here are the matches:
28 and 29 inches: 622 (28 inches rims are more suitable for city bikes, while 29 inches rims are more suitable for mountain bikes).
700C: 622 (700C is used for road bikes, corresponding to the ETRTO 622 diameter).
27.5 inches: 584
26 inches: 559
24 inches: 507
20 inches: 406