The Size Studio
Size Guide: Free Size Converters & Charts (US, UK, EU)
This size guide brings together free converters and charts for shoes, rings, hats, watches, dresses, jeans, belts, shirts, men’s suits and backpacks, in US, UK and EU sizes. Each tool shows the full chart as well as the converter, and says plainly where a figure is a formula, a common convention or only a guideline.
- Shoe Size ConverterUS, UK, EU and cm for men and women, including men-to-women.
- Watch Size for Wrist CalculatorCase diameter, lug-to-lug and strap length for your wrist.
- Hat Size Chart & CalculatorHead measurement to US, UK, EU and S–XXL fedora sizes.
- Ring Size Converter & Printable SizerUS numbers, UK letters, EU, Japan and mm, plus a print-at-home sizer.
- Dress Size ConverterWomen's UK, US, EU, French, Italian, Australian and Japanese sizes.
- Jeans & Trousers Size ConverterWaist sizes to US, UK and EU for men and women.
- Belt Size CalculatorTrouser waist to belt size in inches and centimetres.
- Men's Shirt Size Chart (Neck & Sleeve)Neck size in inches and cm, S–XXL, and what 16/34 means.
- Backpack Size Guide (Litres)Dimensions to litres, and the right size for your trip.
- Men's Clothing Size ConverterSuits, jackets and T-shirts: UK, US, EU and chest sizes.
How to measure yourself well
A converter can only be as good as the number you put into it, and a few habits make home measurements much more reliable.
- Use a soft tailor’s tape measure. If you don’t have one, a strip of paper or a piece of string and a flat ruler will do, as long as you mark the point carefully.
- Measure over thin clothing or bare skin, never over a jumper (sweater) or a coat.
- Keep the tape level and snug, not tight. If it leaves a mark or you are holding your breath, it is too tight.
- Measure twice, and a third time if the first two readings differ. Use the larger figure for shoes, hats and rings.
- Measure at the right time. Feet are best measured in the evening, and fingers can be slightly larger in warm weather.
- Where you can, measure something that already fits: a belt, a ring, a pair of jeans or a shirt collar. That tells you how you like things to fit, which a body measurement alone cannot.
Why sizes vary between brands
Most size labels are conventions, not measurements. Rings and hats come closest to a fixed rule, because their sizes are worked out from a circumference. Clothing and shoe sizes are different: each brand sets its own chart, and there is no single international system that every maker follows.
Cut makes a difference too. A slim-fit shirt and a relaxed one can carry the same size and fit very differently, and stretch fabrics add some give that rigid ones don’t. Shoes are built on each maker’s own lasts, so half a size between brands is normal.
Our converters use the most common conventions, and each page explains exactly where its numbers come from. When a brand publishes its own measurements, trust those for that brand, and use these tools to get close before you check.
FAQs
Are UK and US sizes the same?
Sometimes. Men’s suits, jeans waists and shirt collars use the same numbers in both countries. Women’s clothing differs by 4 (a UK 10 is a US 6), and shoes and hats use different numbers too.
Are EU sizes the same across Europe?
Not for women’s clothing. A German or Dutch 38 is a UK 10, a French or Spanish 38 is a UK 8, and Italian sizes are 2 higher again. Shoe and ring sizes are more consistent across Europe.
Should I size up or down if I’m between sizes?
For shoes, hats and belts, the larger size is usually easier to live with, since insoles, sizing tape or an extra hole can take up the slack. For fitted clothing, go by the measurement that matters most for that garment.