Convert apparel sizes between US, UK, EU, JP, CN, IN - all categories in one tool.
Stop guessing your size when shopping online. Type in a US women's 8, an EU 39, or a UK 6 and instantly see what it is in every other country, plus measurements in cm and inches. Switch between shoe, ring, clothing, and bra categories. Use the sister-size calculator to find the equivalent band/cup combo when one is out of stock.
My Sizes (saved locally - click to remove)
Click "Save as My Size" on any tab to keep your reference card in your browser.
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Equivalent Sizes
| System | Size | Foot Length |
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Equivalent Sizes
| System | Size | Diameter | Circumference |
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Equivalent Sizes
| System | Size | Chest / Bust | Waist | Hip (women) |
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Equivalent Sizes
| System | Size | Notes |
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Sister Size Calculator
| Direction | Band | Cup | Volume |
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Equivalent Sizes
| System | Size | Circumference |
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Pick the category tab (Shoe, Ring, Clothing, Bra, or Hat). Choose the size system you already know (e.g. US women's), pick your size from the dropdown, optionally adjust width or type your measurements directly, and click Convert. The right panel shows the equivalent size in every system plus measurements in cm and inches. Hit Save as My Size to keep a personal reference card across sessions.
Frequently Asked Questions
Why don't you use Mondopoint (cm) for shoes?
Mondopoint (ISO 9407) is the official international standard since 1973 and is used by most countries internally. However, US, UK, EU, JP, CN, IN, and KR each publish their national size based on Mondopoint with country-specific rounding rules (US rounds up to next half, UK rounds down to next half, EU adds a flat 2 to the Paris-point length, JP and CN double the cm). This tool shows Mondopoint in cm in the Foot Length column so you can verify it against your own measurement and cross-reference any country.
What is a sister size in bras?
A sister size is a bra size with the same cup volume but a different band. Because breast volume stays roughly constant when you change bands, going down a band requires going up a cup, and vice versa. For example, 34C has the same cup volume as 32D (sister up) and 36B (sister down). Sister sizing is useful when one band is out of stock but the cup you need is available in another band - the rule is: band diff = -2, cup diff = +1.
How do I measure my ring size?
Wrap a thin strip of paper or string around the base of the finger you want to size. Mark the spot where the paper overlaps, then measure the marked length in mm - that is your inner circumference. Divide by pi (3.1416) for diameter. Our Ring tab accepts either circumference or diameter directly and finds your size in all 5 systems at once. Measure at the end of the day when fingers are warm.
Are men's and women's shoe sizes the same for the same foot?
No. Women's US sizes run about 1.5 to 2 sizes larger than men's US for the same foot length. So a men's US 9 foot wears a women's US 10.5 (or US 11 in some brands). UK and EU sizes follow the opposite convention - men's UK is 0.5 smaller than women's UK for the same foot. JP, CN, and Mondopoint sizes are unisex (same number regardless of gender).
How accurate are these conversion tables?
The tables are derived from ISO 9407 (shoe Mondopoint), ISO 8655 (ring finger circumference), and major retailer published charts (Zappos for shoes, Blue Nile for rings, H&M and Levi's for clothing, Bratabase for bras). Most countries round Mondopoint slightly differently and shoe lasts vary by 3-5 mm by brand, so the size you compute here is the textbook equivalent, not necessarily what fits you in a specific brand. Always check brand-specific size charts when available.
What about kids' and baby shoe sizes?
Kids' (also called "Youth") is for ages ~8-12 and overlaps with adult sizing at the upper end. Baby sizes go up to about US 8 / EU 25 / Mondopoint 15 cm. Kids' sizes use the same international systems as adults but with a different starting point. This converter supports both, with separate drop-downs for each gender category.
Where is my saved "My Size" data stored?
In your browser's localStorage under the key "sizes_my_v1". No server upload, no account, no sync between devices. If you switch browsers or clear browser data, the saved sizes will be lost - export them as a print card before clearing data. Each category tab has its own Save button so you can keep one entry per category.
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