Fit

Measuring for a bra

1 November 2026

A tape, a mirror, and what the two numbers on the label mean.

Two numbers

A bra size is a band and a cup. The band is the measurement around the ribcage. The cup is not a fixed volume: it is the difference between the band and the fullest part of the bust, so a D on a small band holds less than a D on a large one.

Sizing systems label the band differently. A 75 in Germany is a 34 in the United Kingdom and a 90 in France. The size guide on this site lists the common conversions.

Taking the measurements

Measure over a bare ribcage or a thin unpadded bra, standing straight, with the tape level all the way round. The first measurement is snug, directly under the bust. The second is loose, across the fullest part.

Makers publish their own charts, and they do not all agree. Treat your numbers as a starting point, and read the chart of the house you are buying from.

How it should sit

The band does most of the work and should sit level. It should feel firm on the loosest hook when the bra is new, because elastic relaxes with wear. Straps that dig in usually mean the band is too loose. A cup that gapes may be too large, or simply the wrong shape for you.

Check the shop’s returns terms before you order several sizes. Some shops take bras back unworn with their labels, and some do not take certain underwear back at all.

In the shops