BraSizeConversion

Panty Size Calculator

7 sizing systems25+ country calculatorsBands 28-60, cups AA-PZero data stored

Underwear is sized from two measurements, and the hip is the one that decides. Enter your natural waist and fullest hip, and the calculator returns your size, automatically sizing up when your waist runs ahead of your hips, the case where most people get uncomfortable fits.

As always here, the math runs in your browser and nothing is stored.

Measurements

Runs entirely in your browser. Nothing you enter is stored or sent anywhere.

Why hips outrank waists in underwear sizing

A panty has to travel over your hips and then stay put at whatever height its cut targets; the hip measurement determines whether the garment physically fits, while the waistband elastic accommodates a range of waists. Sizing to a smaller waist number when your hips measure larger produces the classic failures: rolling waistbands, riding at the back and dig lines at the leg opening.

Cut changes the height where measurements matter: briefs sit at the natural waist, hipsters and bikinis at the mid-hip, so the same person can wear different printed sizes across cuts of one brand. When between sizes in any cut, take the larger; elastic forgives down, never up.

Frequently asked questions

How do I measure for panty size?
Two tape measurements: your natural waist at the narrowest point, and your hips at the fullest part of your seat, tape level. The hip number chooses the size; the waist number flags when to size up.
Should I size up or down in underwear?
Up, whenever between sizes. Bigger avoids rolling, riding and dig lines, while a size too small produces all three regardless of fabric quality.
Next steps

Last updated August 2026.