Keep it level
Check the mirror. The tape should stay horizontal across your back and front.
Find your fit
Your size should feel like confidence.
Measure in under a minute, get a useful starting bra size, then fine-tune the fit with sister sizing and simple fit checks.
No photos, account or personal details required.
60 sec
Two measurements.
One confident starting size.
Interactive fit finder
Measure. Match. Feel good.
Use a soft measuring tape over a lightly lined or unpadded bra. Keep it level around your body.
- 1 Underbust
- 2 Bust
- 3 Feel
01
Measure your underbust
Wrap the tape directly under the bust. Keep it snug and level, but not tight enough to dig in.
in
Round naturally — the calculator will do the sizing math.
02
Measure the fullest part
Wrap the tape around the fullest point of your bust. Keep the tape parallel to the floor without compressing.
in
Stand naturally and breathe normally while measuring.
03
How do you like your band to feel?
This does not change the core measurement. It helps us suggest the better sister-size direction if you sit between bands.
Your starting point
—
Band—
Cup—
Sister sizes to keep in mind
Firmer band—
Roomier band—
This calculator is a starting guide, not a guarantee. Fit can vary by product, fabric, cup shape and personal preference. Always check product-specific sizing where provided.
Measure it right
Two measurements. Three small rules.
Small changes in tape position can change the result, so keep these checks in mind.
Snug, never squeezed
The tape should touch your body without compressing soft tissue or leaving a deep mark.
Measure naturally
Stand normally, breathe out gently and avoid pulling your shoulders back unnaturally.
Cup difference reference
How the cup estimate works.
Your full-bust measurement minus your underbust measurement gives a starting cup difference. Zeerjama’s existing bra guide uses the same measurement approach.
| Difference | Approx. cm | Starting cup |
|---|---|---|
| 1 in | 2.5 cm | A |
| 2 in | 5.1 cm | B |
| 3 in | 7.6 cm | C |
| 4 in | 10.2 cm | D |
| 5 in | 12.7 cm | DD |
| 6 in | 15.2 cm | E |
| 7 in | 17.8 cm | F |
| 8 in | 20.3 cm | FF |
| 9 in | 22.9 cm | G |
| 10 in | 25.4 cm | GG |
The mirror test
Your bra should support you — not distract you.
Tap the fit issue that sounds familiar.
Band rides up at the back+
The band is likely too loose. Try one band size down and move one cup size up to keep a similar cup volume.
Spillage at the top or sides+
The cup is likely too small or the shape is not right for you. Start by trying one cup size up.
Cups gape or wrinkle+
Try one cup size down. If the volume feels right but gaping remains, a different cup shape may suit you better.
Straps dig into shoulders+
Loosen the straps first. Most support should come from the band. If the band also rides up, try a firmer band and sister-size the cup.
I am between two band sizes+
Use sister sizing: go down a band and up a cup for a firmer feel, or up a band and down a cup for a roomier feel.
Still unsure?
Fit questions are normal.
Share your measurements and the product you are considering. We can help you choose a better starting size without judgment.