Bra Size Calculator
Enter your underbust and bust measurements to instantly find your band size, cup letter and full bra size.
Measure snugly just below the bust, tight but breathable.
Measure at the fullest point of the bust, keeping the tape parallel to the floor.
Why Does Bra Size Matter?
The correct bra size prevents back, shoulder and neck pain while also positively affecting posture. Research shows that the majority of women wear the wrong bra size. Most of the time the problem is not the wrong cup but the wrong band: when the band is too large, support is inadequate and the cup can feel relatively small. This calculator helps you find your size according to the European sizing system using just two simple measurements.
How to Measure. Step by Step
Step 1. Underbust Circumference (Band Size)
Wrap the tape measure just below the breasts, passing under the armpits and around the back. The tape should be horizontal and flat — loose enough to breathe but not sagging. Round the measurement to the nearest whole number. This forms the basis of your band size.
Step 2. Fullbust Circumference (Cup Size)
Pass the tape across the fullest point of the bust, parallel to the floor. A measurement taken without support and with good posture gives a more accurate result. Once you enter this value above, the calculator automatically computes the cup difference.
Calculation Formula
Band Size = If the underbust measurement is an odd number it is rounded up to the next even number (e.g. 77 cm → 78). This is the standard method of the European system; some American sizing guides add +5 to the underbust — this calculator uses the European system common in Turkey.
Cup Letter = Determined by the difference between fullbust circumference and band size. The larger the difference, the larger the cup.
Cup Difference Chart
| Difference (cm) | Cup | Example Sizes |
|---|---|---|
| < 1 cm | AA | 75AA, 80AA |
| 1–2 cm | A | 70A, 75A, 80A |
| 2–4 cm | B | 75B, 80B, 85B |
| 4–6 cm | C | 75C, 80C, 85C |
| 6–8 cm | D | 75D, 80D, 85D |
| 8–10 cm | DD | 75DD, 80DD |
| 10–12 cm | E | 75E, 80E |
| 12–14 cm | F | 80F, 85F |
| 14–16 cm | G | 80G, 85G |
| 16+ cm | H | 80H+ |
This tool is for informational purposes only. Since sizing patterns vary between brands, it is recommended that you try bras on in-store.
Tips for Accurate Measurement
- Ask someone to help rather than measuring yourself — results can be misleading if the tape is not held straight.
- Measure while wearing a non-padded, unlined bra or measure without a bra at all; foam/push-up bras distort the measurement.
- It is important not to pull the tape too tight: for the band measurement the tape should be firm but allow you to breathe.
- Always try bras on in-store after finding your size. The same size can fit differently across brands — especially cup shape and underwire position vary from brand to brand.