Wheel diameter question

[Tony Smith]

The wheel is the standard commercial type built by Budd for Ford, Chevrolet and Chrysler and others, too. It is also of the type used on Mk 1 carriage for Bofors guns (but you knew that already, didn't you Stellan?). It is a 20 inch rim and was available in a variety of rim widths and offsets. The tyre looks to be a 6.00-20, earlier known as a 32x6, which according to Coker tyres , should be about 32.4 inches diameter, or 822mm.
Regarding the wheel, the holes are not usually given a name (unless there is a particularly descriptive shape), this is a five spoke wheel.