Bra Size Calculator (CM)
Enter your measurements in centimeters. This tool gives a practical starting size in EU, UK, and US formats.
How this bra size calculator in cm works
If you’ve been searching for a reliable bra size calculator cm, the key is to combine two measurements: your underbust (band area) and your full bust. This calculator uses those values to estimate your band and cup, then shows equivalent formats in EU, UK, and US sizing.
Keep in mind that bra sizing is a starting point, not an absolute rule. Different brands, fabrics, and cup shapes can fit differently even when the labeled size is the same.
How to measure correctly in centimeters
1) Measure your underbust
- Use a soft tape measure directly under your bust.
- Keep the tape level around your torso.
- Pull snug, but not painfully tight.
- Write the number in cm.
2) Measure your full bust
- Measure around the fullest part of your bust.
- Stand naturally and keep the tape level.
- Do not compress the breast tissue.
- Record in cm.
Band and cup logic (simple version)
The calculator estimates:
- Band size from your underbust measurement.
- Cup size from the difference between bust and underbust.
- Regional conversions so you can shop across international brands.
Example: if underbust is 78 cm and bust is 92 cm, the difference is 14 cm, which typically corresponds to around a C cup in EU-style mapping.
Bra size chart cm (quick reference)
EU band size from underbust
| Underbust (cm) | Approx EU Band |
|---|---|
| 63–67 | 65 |
| 68–72 | 70 |
| 73–77 | 75 |
| 78–82 | 80 |
| 83–87 | 85 |
| 88–92 | 90 |
| 93–97 | 95 |
| 98–102 | 100 |
Cup estimate from bust-minus-underbust difference
| Difference (cm) | Approx 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 |
Understanding sister sizes
Sister sizes keep cup volume similar while changing band tension:
- Go down one band, go up one cup.
- Go up one band, go down one cup.
Example: around 80C EU may feel similar in cup volume to 75D or 85B. This is useful when a band feels too tight or loose but cup volume is close.
Common fit problems and what to change
Band rides up in back
Try a smaller band (or tighter hook position if the bra is new).
Cups wrinkle or gap
Try a smaller cup, or a different cup shape (balconette vs plunge can matter a lot).
Spillage over top or sides
Try a larger cup size, and make sure you scoop tissue into the cup when putting the bra on.
Straps digging in
Straps should not carry most of the support. Usually this means the band is too loose or cup fit is off.
FAQ
Is this calculator accurate?
It is accurate as a starting estimate. Final fit still depends on brand pattern, wire width, cup depth, and personal comfort.
Can breast shape change my size result?
Absolutely. Full-on-top, full-on-bottom, projected, or shallow shapes can all affect which style fits best.
Should I re-measure regularly?
Yes. Weight changes, hormonal shifts, training, pregnancy, and aging can all change bra fit.
Final thoughts
A good bra size calculator in cm saves time and helps you shop smarter. Use the estimate from this tool, then fine-tune with fit checks and sister sizes. Comfort, support, and confidence are the real goals.