Bra Size Calculator

How to use it

1. Wear a non-padded bra or no bra and stand straight in front of a mirror, breathing out normally.
2. Band: wrap the tape snugly around your ribcage directly under your bust. Keep it level all the way round and read the number.
3. Bust, standing: wrap the tape loosely around the fullest part of your bust, level across your back, without squeezing.
4. Bust, leaning: bend forward until your upper body is level with the floor and measure the fullest part again.
5. Bust, lying down: lie on your back and measure once more. Enter any of the three; the calculator averages them.

How the calculation works

This site uses the tape method followed by most current fitting guides: the band is your snug underbust in inches, rounded to the nearest even number, and the cup is the difference between your bust and that band, one letter per inch. Some older guides tell you to add 4 or 5 inches to the underbust for the band. Most modern guides no longer do this, and it tends to give a looser band and smaller cup. If you are used to that method, your result here may show a smaller band and larger cup letter than you expect.

What your result means

Your result is shown in the system you choose, with the same size in the other systems underneath. The size is worked out with the inch method (centimetres are converted first), and the EU, French and Australian sizes are the label conversions of that size, as on most size charts. The sister sizes table shows nearby sizes with about the same cup volume, which is useful if a brand runs tight or loose.

How a well-fitting bra feels

• Band: firm and level, not riding up at the back. A new bra should fit on the loosest hook so you can tighten it as it stretches. You should fit two fingers under the band, but not much more.
• Cups: no gaps at the top and no spilling over the edge or at the sides. The underwire, if there is one, should sit on your ribcage around the breast tissue, not on it.
• Centre: on underwired styles the centre panel usually lies flat against your breastbone.
• Straps: they carry only a small part of the support. If they dig in, the band is often too loose.

Sizes are a starting point

Sizes are not standardised between brands, countries or even styles from the same brand. A calculator gives you a good place to start; how the bra actually feels on your body decides.

Your body also changes, for example with weight changes, training, pregnancy, nursing or age, so it is worth measuring again every so often or whenever a bra stops feeling right.