Find Your Perfect Bra Size ✨
Are you wearing the right size? Body shapes change constantly, and professional fittings aren't always convenient. Estimate your Japan, US, and UK sizes in seconds to shop with confidence.
💡 How It Works
Bra sizing varies significantly by region. This tool converts your measurements into regional standards, whether you’re shopping domestic brands or importing lingerie from the US and UK.
It also calculates your Sister Sizes—alternative sizes that maintain the same cup volume even when the band size changes. Use these to fine-tune your comfort level.
📘 Get an Accurate Measurement
- Level the Tape Keep the measuring tape horizontal to the floor. Measure the fullest part of your bust without pulling the tape tight.
- Toggle Units Switch between centimeters (cm) and inches (in) instantly to match your measuring tape.
- Optimize Your Fit If your current cup feels right but the band digs in or slides up, try the suggested Sister Size for a more comfortable fit.
🧐 FAQ
Why do sizes differ between brands? Every manufacturer uses unique patterns and fabrics. Use this calculator as a standard industry baseline, then check specific brand size charts for the final word.
When is the best time to measure? Measure during a "neutral" time in your cycle. Hormonal changes can cause temporary fluctuations in breast volume.
📚 Trivia
The "cup" lettering system (A, B, C, D) wasn't standardized until the late 1930s. Before then, bras were sold primarily by band size. Because cup volume is relative to the band, a 34B actually holds the same volume as a 32C or a 36A. That’s the science behind Sister Sizes! 👙