Select cup size to see conversion table:
AA Cups | A Cups | B Cups | C Cups |
D Cups | DD/E Cups | DDD/F Cups | DDDD/G Cups |
H Cups | I Cups | J Cups | K Cups |
L Cups | M Cups | N Cups | O Cups |
P Cups | R Cups | S Cups | T Cups |
In this guide, we have US bra size conversion chart that you can download and use for reference. Generally, American lingerie manufacturers size their underthings in inches and centimeters. On the other hand, UK and EU lingerie manufacturers use the metric system, i.e. centimeters.
Bra Size Convention
In the charts, US bra sizes are abbreviated as US. When buying a bra, you will usually find the abbreviation used together with the size. For example, “US 36B” or “36B US”.
Most international stores have bras that are size using US convection.
In US bra sizing, bras are measured in inches. In the bra size guides below, the letter represents the cup size while the measurement represents the bra band size.
US band sizes are divided in steps of 2 inches. When we say “band size”, we are referring to the measurement above bust. However, the band measurement is usually done under bust. This explains why the band size label and the band size measurements are not identical.
Always round down to the nearest multiple of 2 inches and add four (+4) inches. For example, measurement 27 inches is rounded down to 26. Adding four gives us 30, which is the band size.
The most common band sizes are 32, 34, 36 and 38. In European and International bra sizing, the measurements are 70, 75, 80 and 85. American band naming and measurements are identical with British (UK).Cup sizes refer to the difference between over bust and the rounded down under bust measurements.
Sizes start with A, which represent an over/under bust difference of 4-5 in. The sizes continue alphabetically in steps of 1 inch with B (5-6 in), C (6-7 in) etc. Due to demand, sizes smaller than A were introduced and are named AA (one size smaller than A) and AAA (two sizes smaller than A).
Always calculate the difference to rounded down measurement.
Example of How to Calculate the Cup Size
If your over bust measures 39 inches and the under bust measurement is 33 inches, the 33 needs to be rounded down to 32. In this case, the band size would be 36 (32+4) while the cup size would be 39-32 = 7 (note that 32 is the rounded down measurement).
A difference of 7 inches gives us a D-cup. 7 inches is between C and D-cup but cups should not squeeze your bust. When between two cup sizes, choose the larger one.
The US bra size charts below are based on actual, precise measurements. You will not need to recalculate as in the example above.
In the past decades, US lingerie manufacturers used multiples of “D” when naming the cup sizes. For example, you come across “DD” (double dees) and “DDD”. Some bra brands still use this naming convention.
However, most US bra brands are transitioning to using E instead of DD, F instead of DDD, etc. You’ll still find both variant being used today. As a result, US cups are sometimes labeled showing both naming conventions, e.g., “E/DD” and “F/DDD”.
On this page, you’ll find US bra size charts showing measurements in both centimeters (cm) and inches (in). The cup and band measurements are also shown.