Calculate Your EU Bra Size
Enter your measurements to get an estimated European bra size. Use a soft measuring tape and keep it level around your body.
How this EU bra size calculator works
This calculator gives you an estimated EU bra size based on two measurements: your underbust and full bust. The result is formatted in standard European notation, such as 75C, 80D, or 70E.
The calculation follows a practical fitting approach:
- Band size is rounded to the nearest EU 5 cm step (for example, 73 cm becomes 75).
- Cup size is estimated from the difference between bust and underbust measurements.
- You also get sister sizes, which can help when a specific brand runs tight or loose.
Step-by-step: take accurate measurements
1) Measure your underbust
Wrap the tape directly beneath your bust, keeping it horizontal all the way around your torso. Exhale normally and keep the tape snug. This number controls your band size.
2) Measure your full bust
Measure around the fullest part of your chest, usually over the nipples. Keep the tape parallel to the floor and not overly tight. This number, compared to your underbust, determines cup volume.
3) Enter values and calculate
Choose centimeters or inches, enter both numbers, then click Calculate EU Size.
Understanding EU bra sizing
EU sizes use a number + letter format:
- Number (band): 60, 65, 70, 75, 80, 85, 90, etc.
- Letter (cup): AA, A, B, C, D, E, F, G, H, and beyond.
As band size changes, cup volume also changes. That is why sister sizes are useful. For example, 80C has a similar cup volume to 75D and 85B.
Quick EU cup difference reference
The table below shows a commonly used approximation for cup estimation from the bust-minus-underbust difference.
| Difference (cm) | Estimated Cup |
|---|---|
| < 10 | AA |
| 10–11.9 | A |
| 12–13.9 | B |
| 14–15.9 | C |
| 16–17.9 | D |
| 18–19.9 | E |
| 20–21.9 | F |
| 22–23.9 | G |
| 24–25.9 | H |
Common bra fitting mistakes
- Band too loose: Most support should come from the band, not the straps.
- Cup too small: Overflow at the top or sides often means you need a larger cup.
- Straps over-tightened: Tight straps can cause shoulder pain and still not improve support.
- Ignoring brand differences: Some brands fit tighter in the band or shallower in the cup.
How to know your fit is good
- The center gore lies flat against the chest (for wired bras).
- The band is level and does not ride up your back.
- You can fit about two fingers under the band comfortably.
- Cups contain breast tissue without gaping or spilling.
- You feel supported even if straps are slightly loosened.
FAQ
Is this calculator exact?
No online calculator is perfect. This gives a strong starting point, but final fit depends on breast shape, bra style, and brand-specific sizing.
Can I use inches instead of centimeters?
Yes. Select inches in the calculator and it will convert automatically before calculating your EU size.
What if the calculated size feels off?
Try sister sizes and test nearby options (for example, one band up/down and one cup up/down). Small adjustments often solve most fit issues quickly.
Note: This tool is educational and intended as a fitting guide. For complex fit concerns, professional in-store fitting can be very helpful.