1
Measure your underbust
Wrap the tape snugly around your ribcage, directly beneath your bust. Exhale and read the measurement — this sets your band size.
Bra Size Guide
Up to 80% of women wear the wrong bra size. Two quick measurements are all it takes to find a fit that feels like it was made for you.
How to Measure
Three steps,
two minutes
Stand straight in front of a mirror, keep the tape parallel to the floor and breathe normally. A soft measuring tape works best.
2
Measure your bust
Measure loosely around the fullest part of your bust without compressing it. Keep the tape level across your back.
3
Calculate your size
The difference between bust and underbust gives your cup. Use our calculator above — it does the maths and converts it for you.
- Measure in the morning, when you’re most relaxed.
- Wear a light, non-padded bra or no bra at all.
- Keep the tape level — don’t let it dip at the back.
- Re-measure every 6 months; bodies change.
Size Charts
International conversions
All LUNEA sizes follow EU sizing. Use these charts to convert from the size you usually wear.
Band size
| Underbust (cm) | EU | FR | UK / US |
|---|---|---|---|
| 63 – 67 | 65 | 80 | 30 |
| 68 – 72 | 70 | 85 | 32 |
| 73 – 77 | 75 | 90 | 34 |
| 78 – 82 | 80 | 95 | 36 |
| 83 – 87 | 85 | 100 | 38 |
| 88 – 92 | 90 | 105 | 40 |
| 93 – 97 | 95 | 110 | 42 |
Cup size
| Difference (cm) | EU / FR | UK | US |
|---|---|---|---|
| 10 – 11 | AA | AA | AA |
| 12 – 13 | A | A | A |
| 14 – 15 | B | B | B |
| 16 – 17 | C | C | C |
| 18 – 19 | D | D | D |
| 20 – 21 | E | DD | DD / E |
| 22 – 23 | F | E | DDD / F |
| 24 – 25 | G | F | G |
| 26+ | H | FF | H |
Our bra range is available from 70A to 90D. Selected styles also come in XS–XL for wireless bralettes.
| LUNEA | EU | UK | US | Waist (cm) | Hips (cm) |
|---|---|---|---|---|---|
| XS | 34 | 6 | 2 | 60 – 64 | 86 – 90 |
| S | 36 | 8 | 4 | 65 – 69 | 91 – 95 |
| M | 38 | 10 | 6 | 70 – 74 | 96 – 100 |
| L | 40 | 12 | 8 | 75 – 80 | 101 – 106 |
| XL | 42 | 14 | 10 | 81 – 86 | 107 – 112 |
Between sizes in briefs? Size up for high-waist styles and thongs, size down for lace hipsters which have more stretch.
| LUNEA | EU | Bust (cm) | Waist (cm) | Hips (cm) | Shapewear control |
|---|---|---|---|---|---|
| XS | 34 | 80 – 84 | 60 – 64 | 86 – 90 | Light |
| S | 36 | 85 – 89 | 65 – 69 | 91 – 95 | Light – Medium |
| M | 38 | 90 – 94 | 70 – 74 | 96 – 100 | Medium |
| L | 40 | 95 – 100 | 75 – 80 | 101 – 106 | Medium |
| XL | 42 | 101 – 106 | 81 – 86 | 107 – 112 | Medium – Firm |
Our satin sleepwear has a relaxed cut. For a closer fit choose one size smaller.
Fit Troubleshooting
Something doesn’t feel right?
A great bra should feel secure without digging in. Find your fit issue and how to solve it.
The sister-size rule
Going down a band? Go up a cup — 75B and 70C share the same cup volume. Going up a band? Go down a cup: 75B ≈ 80A.
Your band is too loose. Try one band size down and one cup size up to keep the same cup volume (e.g. 80B → 75C). Always start on the loosest hook — you can tighten as the bra stretches with wear.
Your cup may be too large, or the style doesn’t suit your shape. Try one cup size down, or switch to a plunge or a stretch-lace bralette that adapts to your shape.
Around 80% of support comes from the band, not the straps. If straps dig in, your band is probably too loose. If they slip, tighten them slightly or try a style with closer-set straps such as our Smooth Comfort Bra.
The wire should sit flat against your ribcage and fully encircle the breast tissue. If it sits on top, go up a cup size. If it pokes at the centre, the band may be too small.
Your cups are too small. Go up one cup size — and if the band feels tight too, try the next band up with the same cup.
Still not sure?
Take the Fit Quiz
Answer five quick questions about your style and comfort and we’ll build a personal edit of pieces that suit you.