Enter your underbust and bust measurements in centimetres or inches and click "Calculate" — the calculator will determine your band and cup size in EU/UA, US, UK, FR, and IT systems.
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How to Take Measurements for a Bra
What you need. A soft measuring tape and a mirror (to ensure the tape remains level and parallel to the floor).
How to measure. You will need to take two primary measurements.
- Underbust Circumference. Exhale and wrap the tape snugly (but not so tight that it pinches) directly beneath your breasts, parallel to the floor.
- Bust Circumference. Wrap the tape around the fullest part of your chest (usually across the nipples). Hold the tape loosely, making sure it does not compress the breasts. It is recommended to wear a thin, unpadded bra for this measurement.
Tip. When measuring yourself, the tape must run horizontally across your back and chest. For convenience, it is often helpful to have someone assist you.
How Bra Sizes Are Calculated
A bra size consists of two parts: a number (e.g., 75) and a letter (e.g., C).
- Band Size (Number). Determined by your underbust measurement. In the European system, this is rounded to the nearest multiple of 5 (e.g., 74 cm underbust corresponds to a 75 band). In the US and UK, the band is measured in inches using traditional charts.
- Cup Size (Letter). Determined by the difference between your bust and underbust measurements. Every 2 cm of difference increases the cup size by one step (e.g., a 12–13.9 cm difference corresponds to cup A, while 14–15.9 cm corresponds to cup B).
Band Size Correspondence Chart
| Underbust (cm) | Europe / Ukraine (EU/UA) | US / UK | France / Spain (FR/ES) | Italy (IT) |
|---|---|---|---|---|
| 63–67 | 65 | 30 | 80 | 1 |
| 68–72 | 70 | 32 | 85 | 2 |
| 73–77 | 75 | 34 | 90 | 3 |
| 78–82 | 80 | 36 | 95 | 4 |
| 83–87 | 85 | 38 | 100 | 5 |
| 88–92 | 90 | 40 | 105 | 6 |
| 93–97 | 95 | 42 | 110 | 7 |
| 98–102 | 100 | 44 | 115 | 8 |
| 103–107 | 105 | 46 | 120 | 9 |
| 108–112 | 110 | 48 | 125 | 10 |
Cup Size Correspondence Chart (by Difference)
| Bust-Underbust Difference (cm) | EU Cup | UK Cup | US Cup |
|---|---|---|---|
| 10–11.9 | AA | AA | AA |
| 12–13.9 | A | A | A |
| 14–15.9 | B | B | B |
| 16–17.9 | C | C | C |
| 18–19.9 | D | D | D |
| 20–21.9 | E | DD | DD / E |
| 22–23.9 | F | E | DDD / F |
| 24–25.9 | G | F | G |
| 26–27.9 | H | FF | H |
| 28–29.9 | I | G | I |
| 30–31.9 | J | GG | J |
Frequently Asked Questions
What are "sister sizes" in bra fitting?
Sister sizes are sizes that have the same cup volume but different band measurements and cup letters. For example, if a 75B is too tight around your ribs, try a sister size of 80A. The cup volume remains the same, but the band will feel more comfortable.
How often should I measure my bra size?
It is recommended to measure every 6–12 months, or after significant weight gain/loss, pregnancy, or starting a new fitness routine, as body shape and breast size can change over time.
Why do my bra underwires dig into the sides or front?
This typically indicates that the cup size is too small. Try a bra with a larger cup letter but the same band size (e.g., move from a 75B to a 75C).
Is there a difference between sizes of different brands with the same labeling?
Yes, and sometimes it can be significant. This is especially true for US and UK brands: cup sizes like DD, DDD, E, and F are labeled differently depending on the manufacturer. Always check the specific brand's size chart when ordering online, and read customer reviews regarding size accuracy if possible.
Looking for a matching dress or outerwear size? Use our clothing size calculator.