Shoe Size Converter

About Shoe Size Converter

How Shoe Size Systems Differ

Each major sizing system uses a different scale, origin point, and increment size.

System	Unit	Increment	Used In
US	Barleycorn (1/3 inch)	1/3 inch per full size	United States, Canada
UK	Barleycorn (1/3 inch)	1/3 inch per full size	United Kingdom, Australia, New Zealand
EU (Paris point)	2/3 cm (~6.67mm)	2/3 cm per size	Continental Europe, most of Asia, South America
cm (Mondopoint)	Centimetres	0.5 cm	Japan, Korea, ISO standard (military, skiing)

US and UK sizes both use the barleycorn system but start from different zero points, which is why there is a consistent offset between them.

Men's Size Conversion Reference

US Men's	UK	EU	Foot Length (cm)
7	6.5	40	25.0
8	7.5	41	26.0
9	8.5	42.5	27.0
10	9.5	44	28.0
11	10.5	45	29.0
12	11.5	46	30.0
13	12.5	47.5	31.0

Women's Size Conversion Reference

US Women's	UK	EU	Foot Length (cm)
5	3	35.5	22.0
6	4	36.5	23.0
7	5	37.5	24.0
8	6	39	25.0
9	7	40	26.0
10	8	41	27.0
11	9	42	28.0

US women's sizes run approximately 1.5 sizes higher than US men's for the same foot length. A women's US 9 and a men's US 7.5 both fit a 26 cm foot.

How to Measure Your Foot

Step	What to Do
1	Place a sheet of paper against a wall on a hard floor
2	Stand on the paper with your heel touching the wall (wear the socks you would normally wear with shoes)
3	Mark the tip of your longest toe with a pen
4	Measure from the wall edge to the mark in centimetres
5	Measure both feet - use the longer measurement

Feet swell during the day, so measure in the afternoon or evening for the most accurate result. Foot length in centimetres is the most reliable way to find your size when shopping internationally, because it removes the ambiguity between sizing systems.

Why Sizes Vary Between Brands

Factor	How It Affects Fit
Last shape	The mould a shoe is built around varies by brand - some are wider, some narrower
Width options	Some brands offer narrow (B), standard (D), and wide (E/EE) widths; others have one width only
Vanity sizing	Some fashion brands label shoes slightly smaller than the true measurement
Regional manufacturing	Shoes made in different countries may follow slightly different size charts
Shoe type	Running shoes often fit differently from dress shoes at the same marked size

Standard conversion charts (including this one) give you the best starting point, but always check the brand's specific size guide when buying online. Many brands publish their own foot-length-to-size tables that account for their unique last shapes.

Children's Size Notes

Children's shoe sizes use a separate scale that resets around age 6, when kids move from "toddler" to "little kid" sizes in the US system, and then again around age 12 when they transition to adult sizes. Children's feet grow rapidly - the American Academy of Pediatrics notes that toddlers typically gain roughly half a shoe size every 2-3 months, slowing to one full size every 4-6 months by age 5. The converter includes the full children's size chart with US, UK, EU, and centimetre measurements.

Age Range	US Range	Typical Foot Length (cm)	Measure Every
0-12 months	0C - 4C	8.3 - 11.6	6-8 weeks
1-3 years (toddler)	4T - 10T	11.6 - 16.5	8-10 weeks
4-7 years (little kid)	10K - 3Y	16.5 - 22.5	3-4 months
8-12 years (big kid)	3Y - 7Y	22.5 - 25.0	4-6 months

How Does the Barleycorn System Work?

Each full shoe size is a 1/3-inch (8.47 mm) increment, a unit called a barleycorn. The UK scale begins at size zero at 4 inches of last length, while the US scale starts at size one, which is why a US men's size runs one number higher than the UK size for the same physical shoe. The three-barleycorns-per-inch convention dates to the 10th century Welsh Laws of Hywel Dda and was codified by the 13th century English Composition of Yards and Perches. Robert Gardiner's 1856 Illustrated Handbook of the Foot applied it to shoes, anchoring the modern system.

Worked example: A last that is 11 inches long (27.94 cm) fits a foot of roughly 27 cm. Starting from the UK zero point of 4 inches, 11 inches is 7 inches longer - 21 barleycorns, which is UK size 10.5 (half sizes count as 1/6-inch). The US adds one full size, giving US men's 11.5, matching the Mondopoint 270 standard for a 270 mm foot.

What Is the Mondopoint System?

Mondopoint, defined by the ISO 9407:2019 international standard, measures shoe size as the foot length in millimetres rather than as an abstract number. A size marked 270/100 means a 270 mm foot length and a 100 mm foot width. Standard grading uses 5 mm increments for casual footwear and 7.5 mm for protective footwear. Mondopoint is the dominant system in Japan, Korea, China, and Russia, and is used globally for ski boots, skates, military footwear, and pointe ballet shoes because it eliminates the arbitrary offsets of UK/US scales.

If you know your foot length in centimetres, Mondopoint gives you the closest thing to a universal size. The table above shows that 27 cm is a US men's 9, UK 8.5, EU 42.5 - but in Mondopoint it is simply 270. International Organization for Standardization data indicates adult foot width typically falls between 90 mm and 110 mm, which is why some brands now publish a second Mondopoint number to distinguish narrow and wide fits.

Why Do EU Sizes Use Paris Points?

The European system uses a Paris point of 2/3 cm (6.67 mm), roughly 80% the size of a barleycorn, which is why EU sizes step up faster than UK or US ones. The Paris point was standardised in the 19th century by French shoemakers and spread across continental Europe. A full EU size covers 6.67 mm of last length, so the jump from EU 42 to EU 43 corresponds to an extra 6.67 mm - smaller than the 8.47 mm jump from UK 8 to UK 9. This is why EU shoes use half-sizes less frequently than US or UK shoes: the underlying increment is already finer.

International Sizing Quick Reference

Country / System	Base Unit	Half Sizes Common?	Where Used
US / Canada	Barleycorn (1/3 inch)	Yes	Starts at size 1
UK / Ireland / Australia	Barleycorn (1/3 inch)	Yes	Starts at size 0
EU (Paris point)	6.67 mm	Less common	Continental Europe, Brazil
Mondopoint (ISO 9407)	Millimetres of foot length	5 mm steps	Japan, Korea, China, ski and military
Japanese JIS S 5037	Centimetres of foot length	0.5 cm steps	Japan (compatible with Mondopoint)

Common Mistakes When Converting Shoe Sizes

The most common mistake is assuming men's and women's numbers convert 1:1. Women's US sizes run roughly 1.5 numbers higher than men's for the same foot length - a unisex sneaker sold as men's US 8 fits the same foot as a women's US 9.5. A second mistake is ignoring width. Two people with identical 27 cm foot lengths can need different shoes if one has an E width (wide) and the other a B width (narrow). Third, children's conversions can trip up parents, because the US children's scale resets at 13K, then restarts at 1Y (youth). A US 13K is smaller than a US 1Y by one full size.

Brand drift is real: Nike running shoes tend to fit about half a size small, while Adidas Ultraboost usually fits true to size, and Converse Chuck Taylors run about one full size large. When buying online, check the brand's own foot-length-to-size chart. Use the CM to Inches Converter to double-check your foot measurement, and the Length Converter for any other measurements listed on international size guides.

How Should a Shoe Fit?

A well-fitting shoe should have 1 cm to 1.5 cm (about a thumb's width) of space between the longest toe and the front of the shoe when standing. The ball of the foot should sit at the widest part of the shoe, and the heel should not slip when walking. Tightness across the top of the foot usually indicates you need a wider width rather than a longer size. Shopping later in the day matters: a 2016 study in the Journal of Foot and Ankle Research found adult feet expand by 4% to 6% in length and up to 8% in volume over a full day of standing and walking.

Fit Signal	What It Means	Action
Toes touch the front	Shoe is too short	Go up half a size
Heel slips on every step	Shoe is too long or too wide	Go down half a size, try narrower width
Ball of foot hits the arch	Shoe is too long	Go down half a size
Pinching across the top	Need a wider width (E or EE)	Same length, wider fitting
Little toe presses the side	Need a wider width	Same length, wider fitting

For sports footwear the rules shift. Running shoes usually go up half a size from your dress shoe size to allow for foot swelling during long runs. Climbing shoes are often bought one to two sizes below street size for a tighter, performance fit. Ski and snowboard boots use Mondopoint directly and should be snug around the heel with the toes just touching the front when standing upright.

Sources

• ISO 9407:2019 - Footwear sizing, Mondopoint system
• Wikipedia - Shoe size systems and history
• SATRA Technology - The diversity of footwear sizing systems
• ANSI - ISO 9407:2019 Footwear Sizing explainer
• NHS - Child growth and measurement guidance
• American Academy of Pediatrics - Toddler development