Ring Size, Shoe Size & Hat Size Converter – International Chart
Convert between US, UK, EU, Japanese and metric sizes, or measure yourself and find your size in every system. Runs in your browser — nothing is uploaded.
- 100% free
- No sign-up
- Nothing uploaded
- No watermark
- No limits
- No bullshit
Measure your finger
Ring size chart
| US / Canada | UK / AU | EU / ISO | Japan | Diameter mm | Circumference mm | Circumference in |
|---|
To measure: wrap a strip of paper snugly around the base of the finger, mark where it overlaps and measure the length in mm — that is the circumference. Or measure the inside diameter of a ring that already fits. Fingers swell in heat and shrink in cold, so measure at the end of the day at room temperature.
Men's shoe size chart
| US | UK | EU | cm | Inches |
|---|
Kids' sizes: C = child (toddler and little kid), Y = youth (big kid). Youth 1Y follows child 13C. Foot lengths include a small allowance for the shoe, which is why they are slightly longer than a bare foot.
Hat size chart
| Head cm | Head inches | US size | UK size | Letter |
|---|
Measure around the widest part of the head, just above the ears and eyebrows, with the tape snug but not tight. US and UK hat sizes are the head diameter in inches (circumference ÷ π); UK sizes run ⅛ smaller than US for the same head.
Sizes vary between brands. These charts follow the most widely used standards (ISO 8653 for rings, Brannock-derived tables for shoes), but a Nike 10 is not the same as an Adidas 10, and ring sizes can differ by half a size between jewellers. When in doubt, measure and check the brand's own chart.
How to use
- Pick a tab. Choose ring, shoe or hat, and for shoes pick men's, women's or kids'.
- Enter what you know. Select the system you have (a US size, a UK letter, a measurement in mm or cm) and type the value. The converter finds the nearest match in every other system instantly.
- Check the chart. The matching row is highlighted in the full table so you can see the neighbouring sizes if you are between two.
FAQ
What is a US ring size 7 in UK and EU?
US 7 is UK/Australian N½, EU/ISO 54 (the circumference in mm, 54.4), and Japanese 14. The inside diameter is 17.3 mm.
How do I convert US shoe sizes to EU?
There is no exact formula because EU sizes are based on ⅔-cm "Paris points" while US sizes are based on ⅓-inch barleycorns. As a rule of thumb, men's EU ≈ US + 33 and women's EU ≈ US + 30.5, but use the chart for the accurate mapping.
Why are men's and women's US shoe sizes different?
They use the same length scale, but the women's numbering is offset: a women's US 9 is the same foot length as a men's US 7.5. UK sizes use a single scale for both, which is why UK sizes look smaller for women.
What hat size is 58 cm?
58 cm is 22.8 inches around, which is US size 7¼ (UK 7⅛), usually sold as Large. Medium covers roughly 56–57 cm and X-Large 60–61 cm.
Simple Desk Tools vs. the usual suspects
| This tool | Typical "free" tool sites | |
|---|---|---|
| Price | Free, forever | Free tier, then paywall |
| Account | None — open the page and go | Sign-up or email required |
| Your files | Stay on your device; nothing is uploaded | Uploaded to their servers, kept for hours |
| Watermark | None | On the free tier |
| Limits | None — any size, any number of files | Daily caps and file-size limits |
| Speed | Instant — runs in your browser | Queue, upload, wait, download |
The no-bullshit promise: no registration, no upsell, no "premium" button, no watermark, no file limits, and your files never leave your computer. The site is paid for by a couple of ads, nothing else.
Privacy: your measurements are processed on your device only and never sent anywhere.