GenderSizer is a free online tool that converts sizes between men's and women's sizing systems for shirts, jeans, and shoes. No signup, no app to download — pick a category, choose a size, and get the equivalent instantly.
Clothing brands use completely different sizing systems for men and women, and there's no obvious way to translate between them. That's a real problem for a lot of people: someone buying a gift for a partner, shoppers who prefer the fit or styles from the "other" section, sneaker fans whose favorite release only comes in one gender's sizing, and people whose bodies simply fit better in clothing that wasn't labeled for them.
Before GenderSizer, answering a simple question like "what is a men's medium in women's sizes?" meant digging through forum threads, brand-specific charts, and conflicting blog posts. We put the standard conversions in one place, organized by category, with the fit notes that actually matter — like the fact that men's shirts are cut boxier, or that US women's shoe sizes run 1.5 sizes higher than men's for the same foot.
Our conversions reflect standard US sizing conventions. They're a reliable starting point, but sizing always varies between brands — a medium at one retailer can fit like a large at another, and "vanity sizing" means many labels run bigger or smaller than their stated measurements. Wherever possible we show the underlying body measurement (chest, waist, or foot length) alongside the size label, so you can double-check against any brand's own chart. For expensive purchases, confirm with the brand's chart before buying.
Spotted an error in a conversion, or want a category added? We'd like to hear from you at contact@gendersizer.com.