Hey Margaret.... Just got something buzzing around in my head....
I would like to know : In the British cup sizing regime , 1: Does one cup size equate to 1 inch , for each step up ??
Also , when you get to the sizes where you use the double letter code , i.e. 44gg or 44hh....Is the double g or double h a step of 1 inch or 1 cup size or is it an 'in between' step , in relation to a 44g or 44h?? ..... Would value your knowledge on this....Thanks .
Technically, only the back band truly relates to inches, eg. a 32 back band is 32” around the back (the underbust) with a measuring tape, and to gain your cup size you measure around the fullest part of your bust (the overbust) so, each increase in cup size difference from the underbust to overbust roughly equates to one inch.
However, a zero difference between underbust and overbust starts with AA cup (eg. 32AA would be a 32 back with a 32 overbust).
From there, it increases one inch per cup at a time. This is approximately one inch of “cup” material - but it’s really not that simple, because someone could measure 32” around the back and 36” around the boobs (making them a 32D), but a 32D bra might be uncomfortable or not fit well. They might be more suited to a 34C or a 30DD - which are approximately the same sizes, with the bigger or smaller back band (or cup) compensating for the increase or decrease in cup/back band material.
As for the increase - it’s always an inch each time - irrespective of D, DD, G, GG etc.