How to Measure for a One-Piece Swimsuit
Bust, waist, hips — and the silent fourth measurement that 90% of buyers miss: torso length. Get all four right and the suit doesn't ride up.
The Four Measurements
| Measurement | Where | Why |
|---|---|---|
| Bust | Fullest part, parallel to floor | Cup support fit |
| Waist | Natural waist (narrowest) | Mid-suit fit |
| Hips | Fullest part of seat | Bottom + leg-opening fit |
| Torso length | Shoulder → front → crotch → back → shoulder | Decides ride-up or sag |
The Torso-Length Method
- Place start of tape on highest point of one shoulder.
- Run tape down the front of your body. Tape stays flat against you.
- Pull through the crotch snug. Mimics how the swimsuit fabric will travel.
- Run up the back along your spine.
- Stop at the same shoulder where you started. Total length in inches = torso.
Torso Length to Suit Cut
| Torso length | Build | Suit cut to choose |
|---|---|---|
| ≤55" | Very petite | Short torso (Lands' End Mini, Speedo Petite) |
| 55–58" | Petite | Short torso |
| 58–60" | Average shorter | Regular cut, slight on-the-shorter-side |
| 60–63" | Average | Regular cut |
| 63–65" | Average taller | Regular or long torso |
| 65–67" | Tall | Long torso (Speedo Tall, TYR Long, Lands' End Long) |
| ≥67" | Very tall | Long torso, possibly extra-long |
Common Mistakes
Skipping torso length entirely
Bust + waist + hips alone doesn't tell brands whether to send you a 58" or 65" torso suit.
Sizing up for long torso
Gives a too-loose suit at chest, waist, hips. Use a long-torso CUT instead.
Measuring without crotch tension
Loose tape at the crotch gives a too-long reading. Mimic actual swimsuit fabric.
Buying the same size after years
Bodies change; suits stretch. Re-measure every 1-2 seasons.
FAQs
Why does a one-piece need torso length?
A one-piece is a single loop of fabric — must match your body's torso loop length.
How do I measure my torso?
Shoulder → front → crotch → back → same shoulder.
Typical torso length?
Average 58–63 inches. Petite 55–58. Tall 63+.
Should I size up for a long torso?
No — use long-torso CUT instead.
How should a one-piece fit?
Snug everywhere; stretches when wet.
Do swimsuits stretch over time?
Yes — chlorine degrades elasticity. Cycle two suits if frequent use.
Four Numbers, One Right Suit
For full swimwear sizing across bikinis and trunks see how to measure for swimwear; for bikini-specific cup sizing see bikini measurement.
Selling swimwear on Shopify? Torso length cuts returns.
Tailor Size Guide adds torso length matching to every one-piece listing.