Stand up straight, but don’t puff out your chest like you’re about to arm-wrestle a superhero. Relax. Wrap the measuring tape directly under your bust, where the band of your bra usually sits.
Tighten it until it’s snug—like a firm hug, not a python squeeze. Round this number to the nearest whole inch. If you’re a 32, great. If you’re a 34.5, round up to 35. But wait: if it’s an odd number, add 4 inches. This is the weird math of bra sizing. Don’t question it; just nod and add.
For example: if your underbust is 31 inches, add 4 to get 35. But if your underbust is 32, that’s already even, so your band size is 32. Pro tip: Your band size should be the same number you need to hook on the loosest clasp—because bras stretch over time like our patience at 5 PM.
