Women's Underwear Size Calculator
Reconcile your natural waist and fullest hip measurements across standard alpha sizes (XS–3XL) and traditional numeric panty sizing.
Cut-Specific Fit Analysis
Comfort FirstHow to Measure for Underwear
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1
Measure your fullest hips (Primary)
Stand with feet together and measure around the fullest curve of your buttocks. Hip circumference is the main anchor measurement for bikinis, thongs, and low-rise styles.
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2
Measure your natural waist (Secondary)
Wrap the tape around the narrowest point of your midriff (above the belly button). This measurement determines fit for high-waisted briefs and light control underwear.
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3
Consider silhouette and leg openings
If your hip and waist point to different sizes, choose the larger size. Elastic leg bands should rest flat against the skin without digging into thigh creases.
Frequently Asked Questions
Traditional US panty sizes use single-digit numbers (5 = Small, 6 = Medium, 7 = Large, 8 = XL, etc.). Most modern brands use alpha sizing (XS, S, M, L, XL). Our calculator provides both reference numbers.
For low-rise briefs, bikinis, and thongs, the hip measurement is paramount because the waistband rests across the high hips. For high-waist styles and shaping briefs, your natural waist measurement must be accommodated to prevent rolling down.
During pregnancy and early postpartum, prioritize your expanding low-hip measurement and select ultra-soft, stretchy waistbands that sit gently beneath the bump or non-binding high-waist support. For editor-tested picks designed for changing bodies, see our guide to the best maternity underwear.
Leg bands dig in when the garment's hip circumference is too small or when the leg opening cut conflicts with fuller upper thighs. If you experience wedgies or thigh pinching, size up one size or select high-cut and French-cut leg silhouettes that give thighs unrestricted freedom.