Size conversion, simplified
Find your size in any system.
SizeLoop translates between US, UK, EU, Japanese, and alpha sizing — so you can shop any brand, anywhere, with confidence.
Why SizeLoop exists
One measurement.
Every system.
Sizing isn't universal. The same foot gets a different number in every country. Here's how one measurement travels across systems.
Foot length in centimeters. The most reliable starting point.
US, UK, EU, Japanese — pick the label you need.
SizeLoop maps your measurement to the right size instantly.
Cross-check against the brand's chart before you buy.
Example — foot length:26.2 cm
The same foot. Four different numbers. That's why conversion matters — and why guessing by system alone leads to wrong sizes.
Tool discovery
Every converter.
One place.
Eight precision tools covering footwear, clothing, and accessories — each with verified charts and instant conversion.
US, UK, EU, and JP conversions for men, women, and kids. Foot-length tables cross-checked against brand charts.
Open converter → ApparelClothing Size ConverterLetter and numeric sizes across US, UK, and EU systems.
Open → ApparelWomen's Dress ConverterBust, waist, and hip to international dress sizes.
Open → ApparelMen's Dress ShirtNeck and sleeve measurements.
Open → DenimJeansWaist and inseam conversions.
Open → AccessoriesHatHead circumference to hat size.
Open → AccessoriesRingFinger diameter to ring size.
Open → KidsKids' Shoe ChartUS, UK, EU, JP for growing feet.
Open →Measurement explorer
Start with a
tape measure.
Every conversion begins with a measurement. Pick one to see what it tells you and which converter uses it.
International systems
The world doesn't
agree on sizes.
Five major systems, five different numbers for the same body. Explore how they relate.
US sizing
The most common starting point for American shoppers. US sizes run on their own scale — a US 9 in shoes has no arithmetic relationship to a UK 8 or EU 42.5.
UK sizing
Close to US but offset by one in footwear — a UK 8 equals a US 9. The difference trips up many shoppers ordering from British brands.
EU sizing
Continental European sizes scale differently — they measure foot length in Paris points. An EU 42.5 corresponds to a US men's 9.
JP / Mondo sizing
The most logical system — Japanese Mondo sizes are based on foot length in centimetres, but the label is not your exact foot measurement. Brands build in wearing room, so a JP 27.0 typically fits a foot of about 26.2 cm. Check the brand's foot-length column before you buy.
Alpha sizing
XS through XXL — the simplest system, but also the vaguest. An "M" varies wildly between brands, which is why measurements matter more than labels.
Why SizeLoop exists
Sizing is inconsistent.
We make it navigable.
International sizing varies by system and by brand. There is no single universal standard — a size 9 in one country is a different number everywhere else.
SizeLoop translates between US, UK, EU, Japanese, and alpha systems using sourced, cross-checked charts. Our conversions are reliable starting points — but brands cut differently, so confirm with the brand's own chart when precision matters.
Charts are sourced and cross-checked where applicable. Conversions are starting points — always verify against the brand's chart.
Learn to measure
Measure right,
fit right.
Step-by-step guides for getting accurate measurements at home.
All you need is paper, a pen, and a ruler. Get your true foot length in under five minutes — the single most useful number for shoe shopping.
Read the guide →Common questions
Questions,
answered.
The things shoppers ask most about sizing and conversion.
Are the converters free?
Which size system should I start with?
Do I need to measure first?
Why does sizing differ between brands?
What should I do if I'm between sizes?
How do kids' sizes work?
Continue exploring
Where to next?
Follow your intent — convert, measure, understand, or browse everything.
All eight size converters in one directory.
Browse converters → MeasureLearn to take accurate body measurements at home.
Read the guide → Understand sizingHow international systems relate — and why they differ.
Learn more → Browse all toolsThe complete SizeLoop toolkit, organized by category.
See everything →