Find your true bra size
Two measurements, every bra type. Enter your underbust and overbust below and we'll match you across band, cup and international sizing — with fit notes for the style you're shopping.
Your measurements
Snug, directly under the bust
cm
Fullest point, tape level
cm
Fullest point, over a light top
cm
For ages 6–18. Age and weight are shown alongside the result as a cross-check — chest is the measurement we size from.
Bra type
Size chart —
How to measure accurately ›
- Wear a well-fitting, unpadded bra — padding and wire shape hide your true measurement.
- Underbust: wrap the tape snugly around your ribcage, directly under the bust, parallel to the floor.
- Overbust: wrap the tape around the fullest part of your bust — usually across the nipple line — without pulling tight.
- Breathe normally and keep the tape level all the way around, front and back.
- Re-measure every 6–12 months, or after any weight change, pregnancy, or surgery — bodies change, and so does fit.
Why band and cup sizes shift between systems ›
US and UK band sizes match, and cups from AA–D are shared too — it's above a D that they split: US repeats letters (DD, DDD), while UK keeps going (DD, E, F, FF). EU/International sizing works entirely differently: the band number is your underbust in centimetres, rounded to the nearest 5, and cups run through a single unbroken alphabet. That's why a US 34G shows up as a UK 34F and an EU 75G — same fit, three labels.
Why this might land differently from a generic formula ›
This tool uses Losha's own size chart — a fixed table of underbust and overbust ranges, in centimetres, built specifically for how their bras fit — rather than a generic international formula. That chart covers underbust 63–107cm and cup A–K; for anything outside that, we'll point you to Losha's fit specialists instead of guessing.
