Your period underwear size, in every brand
Most period underwear can't be returned once tried, so a wrong size is money in the bin. One hip measurement gives you every brand's answer at once - plus which brands run small or large.
Your hip measurement
Measure around the fullest part of your hips and bottom, feet together, tape snug but not tight. It's the one measurement every brand's chart is built on.
Typical range 32–60 inches.
Computed on your device. Your measurement is never sent to us - it's saved only in this browser so you don't have to retype it.
Common questions
- Why does the tool only ask for my hip measurement?
- Hip circumference is the one measurement every period underwear brand publishes in its size chart, so it is the only reliable axis for translating sizes across brands. Waist ranges vary too much between cuts to be the anchor.
- Is my measurement sent to a server?
- No. The size math runs as code in your own browser against published size-chart data. Your measurement is never transmitted, never put in a URL, and never stored on our servers. It is kept only in your browser so you do not have to retype it, and you can clear it with one click.
- Why do I get different sizes at different brands?
- Because the charts genuinely disagree. The same 40-inch hip lands in M at one brand and XL at another, and some brands are known to run small or large relative to their own charts. The tool shows each brand’s published answer plus its runs-small or runs-large reputation.
Next question: what absorbency do you actually need?
Translate my flow