Shoe sizes are conventions, not measurements. No single official standard links US, UK, European and Japanese sizes, and two brands can label the same foot half a size apart (sometimes a full size in EU numbers). The one number that does not change from shop to shop is the length of your foot. This guide shows how to measure it, how each sizing system turns that length into a size, and where the usual conversion charts disagree with each other.

Five parallel scales against foot length from 21 to 31.5 cm: Japanese centimeters, US men's sizes, US women's sizes on the FIA scale, UK sizes and EU Paris-point sizes, with a dashed line at a 26.2 cm foot reading JP 26, US men 9, US women 10, UK 8 and EU 41.5
Chart: where each system's sizes fall on the same foot-length axis, computed from the foot-length formulas below.

Start with your foot length in centimeters

Every conversion below runs through foot length, so measure it first. Do it barefoot or in thin socks, standing, with your weight spread evenly:

  1. Tape a sheet of paper to the floor, flush against a wall.
  2. Stand on it with your heel touching the wall, looking straight ahead, without curling your toes.
  3. Have someone mark the tip of your longest toe (not always the big toe), keeping the pen upright.
  4. Measure from the wall to the mark in millimeters. Repeat for the other foot and use the longer one.

That number is your foot length, not your shoe length. A shoe, and the last (the foot-shaped form it is built on), is longer than the foot. Wikipedia's summary of sizing practice puts the difference at about ½ to ⅔ inch, which is 1.27 to 1.69 cm. Mizuno's measuring guide gives a similar rule of thumb: add 1 to 1.5 cm for shoe length. This gap is the source of most disagreements between charts, because some systems count the foot and others count the last.

How each system works

The formulas below are the approximations given in the Wikipedia article on shoe sizes. SamemaS uses exactly these to build its men's shoe size converter and women's shoe size converter, so the article and the tools agree.

US and UK: the barleycorn

English-speaking sizes count in barleycorns, an old unit of ⅓ inch (8.47 mm). A full size is one barleycorn and a half size is ⅙ inch (4.23 mm). By foot length in inches:

The UK has two scales. Children's sizes start at 0, for a 4 inch last, and run up to 13½. Adult sizing then restarts at 1, which Wikipedia gives as an 8⅔ inch (22.0 cm) last. Our tables cover adult sizes only.

Two US women's scales

US women's sizes are not one scale but two. On the "standard" or FIA (Footwear Industries of America) scale, women's size = men's size + 1. On what Wikipedia calls the "common" scale, women's size = men's size + 1.5. SamemaS uses the FIA scale. On it, a women's 9 is a men's 8 and a UK 7. A brand on the common scale would call the same foot a women's 9.5. US women's to UK is a gap of two sizes on our table (W8 = UK 6), and 2.5 on the common scale.

EU: the Paris point

Continental European sizes count in Paris points of ⅔ cm (6.67 mm), starting from zero length, which is why the numbers are in the high 30s and 40s. Strictly, an EU size is 1.5 × the last length in cm. Written in terms of the foot, Wikipedia gives:

EU sizes are unisex, so the same formula serves men and women. Our tables round the result to the nearest half size.

Japan, China and Mondopoint: the foot itself

Mondopoint, defined in ISO 9407, labels shoes by the foot length they fit, in millimeters, plus a width. Japan's JIS S 5037 uses the same idea in centimeters with 5 mm steps (24, 24.5, 25…) and adds girth letters (A to G, with E, EE, EEE and so on in between). China's GB/T 3293.1 is also Mondopoint-based, so a Chinese 260 is a 26 cm foot. In our tables:

A JP 26 is therefore designed for a foot of about 26 cm, not a 26 cm shoe. Brands still differ in how much room they add, and width matters as much as length.

Bar chart of the length of one size step: Mondopoint 5.00 mm, US and UK half size 4.23 mm, Paris point 6.67 mm, barleycorn 8.47 mm
Chart: one size step in each system. Because the steps differ, sizes never line up exactly and every table has to round.

Men's shoe size chart

These rows are copied from the SamemaS men's table. UK = US − 1 everywhere; EU and JP come from the foot-length formulas.

US menUK / AUEUJP / Mondopoint (cm)China (mm)Foot (in)Foot (cm)
5436.5232309.0022.9
6537.523.52359.3323.7
763924.52459.6724.6
874025.525510.0025.4
8.57.540.52626010.1725.8
9841.52626010.3326.2
9.58.54226.526510.5026.7
10942.52727010.6727.1
1110442828011.0027.9
1211452929011.3328.8
131246.529.529511.6729.6
141347.530.530512.0030.5

US 8.5 and 9 both round to JP 26. That is expected: ⅓ inch steps (8.47 mm) don't line up with 5 mm steps, so now and then two US half sizes land in the same Japanese size.

Women's shoe size chart

US women's sizes on the FIA scale, copied from the SamemaS women's table.

US womenUK / AUUS menEUJP (cm)China (mm)Foot (cm)
534352222022.0
64536.52323022.9
75637.523.523523.7
8673924.524524.6
9784025.525525.4
108941.52626026.2
1191042.52727027.1
121011442828027.9
Myth check: "a women's 9 is a men's 7.5"

That is only true on the "common" scale, where women's = men's + 1.5. On the FIA scale used here, a women's 9 is a men's 8. When a chart or a friend gives a women's to men's conversion, ask which scale it uses, or skip the question and compare foot length in centimeters instead.

Why brand charts often show a bigger EU size

Put a men's US 10 into many retail charts and you will see EU 43 or 44. Our table says 42.5. Both can be right, because they measure different things. The foot formula gives 1.5 × 27.1 + 2 = 42.6, which rounds to 42.5. A chart built on last length starts from a longer number: on Wikipedia's last formula, a US 10 has a last of (10 + 24) ÷ 3 = 11.33 in, or 28.79 cm, and 1.5 × 28.79 gives EU 43.2. Brands then add their own allowance on top.

So treat EU conversions as accurate to about one size in either direction. If a brand publishes a chart with foot lengths in centimeters, trust it over any generic table, including ours. If it doesn't, read reviews for comments like "runs small" before you order.

Worked example: one foot through every system

A foot measures 262 mm on the paper-and-wall test. Here is the full conversion:

  1. Convert to inches: 26.2 ÷ 2.54 = 10.31 in.
  2. US men: 3 × 10.31 − 22 = 8.94, which rounds to US men's 9.
  3. US women (FIA): 3 × 10.31 − 21 = 9.94, so US women's 10 (10.5 on the common scale).
  4. UK: 3 × 10.31 − 23 = 7.94, so UK 8.
  5. EU: 1.5 × 26.2 + 2 = 41.3, which rounds to EU 41.5. Expect many brands to call this EU 42 or 43.
  6. Japan and Mondopoint: 26.2 cm rounds to JP 26; in China that is 260.

Check the result against the table: the US men's 9 row shows UK 8, EU 41.5, JP 26 and a 26.2 cm foot. If your foot sits between two rows, try both sizes where you can, or check the brand's chart for the foot-length range each size covers.

Width, and what the letters mean

Length is only half of fit. Width designations differ by country and are not interchangeable:

Close-up of an old metal foot-measuring device with a central sliding scale lettered from AAAA to EEE for width and numbered side scales for length
A mid-20th-century foot-measuring device (about 1940s–1950s) in the Auckland Museum collection. The central scale, lettered AAAA to EEE, reads US width; the numbered side scales read length. Photo: Auckland Museum, CC BY 4.0, via Wikimedia Commons (resized).

If you have wide feet, measure the girth too: wrap a soft tape around the widest part of the foot, across the joints of the big and little toes, while standing. Mizuno's guide, for example, measures girth this way to choose a Japanese width.

Using the SamemaS shoe size tables

The men's and women's shoe size converters are lookup tables, not calculators. Pick a column (US, UK / AU, EU, JP / Mondopoint, China, foot length in inches or centimeters), choose a value, and the matching row is highlighted. Men's sizes run from US 5 to 15 and women's from US 4 to 13. The easiest way in is the Foot (cm) column: choose the value closest to your measurement and read across. To convert your measurement between inches and centimeters first, use the length converter. For clothes, the same idea applies to chest and bust measurements; see our guide to international clothing size charts.

Quick checklist

Frequently asked questions

1Is there an official shoe size conversion standard?
No. There is no single official standard that links US, UK, EU and Japanese sizes. ISO 9407 (Mondopoint) and Japan's JIS S 5037 label shoes by foot length, and the technical specification ISO/TS 19407 offers conversion tables, but brands still differ by about half a size. Measure your foot in centimeters and check the brand's own chart.
2What is a US men's 10 in EU and UK sizes?
On the SamemaS table, which uses the foot-length formulas, a US men's 10 is UK 9, EU 42.5 and JP 27 (a 27.1 cm foot). Many brand charts list it as EU 43 or 44 because they are based on the longer shoe last, so the brand's own chart should win.
3What is a women's 9 in men's sizes?
It depends on the scale. On the FIA scale used by SamemaS, women's = men's + 1, so a women's 9 is a men's 8 and a UK 7. On the common scale, women's = men's + 1.5, so a women's 9 is a men's 7.5.
4How do I find my Japanese shoe size?
Measure your foot from heel to longest toe in centimeters while standing, and round to the nearest 0.5 cm. Japanese sizes (JIS S 5037) label the foot length, so a 26.2 cm foot is a JP 26. Width is shown separately with girth letters such as E or EE.

Sources

  1. Shoe size — Wikipedia
  2. ISO 9407:2019 Shoe sizes: Mondopoint system of sizing and marking — International Organization for Standardization
  3. ISO/TS 19407:2015 Footwear: Sizing: Conversion of sizing systems — ANSI Webstore
  4. How to measure your foot size (foot length, foot girth) — Mizuno