When measuring bra size at home, there are two elements to consider: the band and the cup.
To measure the band:
Stand upright without a bra on.
Get a tape measure and measure around your back and under your boob, i.e. where the band of a bra usually sits.
Jot down how many inches this is. If itâ€s an even number, thatâ€s your band size. If itâ€s an odd number, round it up.
To measure the cup:
Put on your most comfortable bra. Your boobs are now in their optimal position, so thatâ€s what you want to measure.
Wrap the tape measure around your front and back, but this time in line with the fullest part of your bust.
The difference in inches between this and your band size is your cup size: