Shoe Size Converter

There are four major shoe sizing systems used worldwide.

• The US system (Brannock scale) is used in the United States and Canada, with separate scales for men, women, and children.
• The EU system (French Paris point) is used across Europe and is unisex — a EU 42 is the same length for men and women.
• The UK system is used in Britain, Ireland, Australia, and New Zealand, and is similar to the US system but offset by about 0.5 to 1 size for men.
• The JP system, used in Japan and much of East Asia, is the simplest — it equals the foot length in centimeters.

All systems ultimately map to foot length, making centimeters the universal translation layer.

Even within the same sizing system, a size 10 from Nike may feel different from a size 10 from Adidas. This is called vanity sizing or last variation — each brand uses slightly different shoe lasts (foot-shaped molds) and may round sizes differently.

The best way to ensure a good fit when buying from an unfamiliar brand is to measure your foot length in centimeters and compare it to the brand's specific size chart.

Our converter provides the standard industry conversions, which work as a reliable starting point for most major brands.

To convert a US shoe size to EU, add roughly 33 to a US men's size (US 10 = EU 43) or 31 to a US women's size (US 8 = EU 39).

The exact relationship stems from the underlying foot length, since the European system uses the Paris Point where each size equals 6.67 mm (two-thirds of a centimeter). Because US sizes increment by one-third of an inch (8.47 mm) and EU sizes increment by 6.67 mm, the offset drifts slightly across the range, so half-size rounding is common.

The ISO 9407 Mondopoint standard resolves this by expressing size directly as foot length in millimeters, the most reliable cross-system reference.

Measure foot length by standing on a sheet of paper, marking the heel and the tip of the longest toe, then measuring the distance in centimeters. Standing matters because the foot spreads under body weight, adding up to half a size.

This centimeter measurement is the universal base for every system: it is your Japanese (JP) size directly, and it feeds the US, EU, and UK conversions.

ISO 9407:2019 formalizes this approach through the Mondopoint system, which defines shoe size as the mean foot length in millimeters plus a width grade. Measuring in the afternoon accounts for natural daily swelling, giving the most representative fit.

Shoe size formulas convert foot length into system-specific numbers.

• The Japanese system is trivial: JP size equals foot length in centimeters.
• The European Paris Point system uses EU size approximately equal to foot length in cm multiplied by 1.5, then plus about 2, because each Paris Point spans 6.67 mm.
• The US men's Brannock formula is roughly US = (3 x foot length in inches) minus 22, since 1 inch = 2.54 cm exactly per NIST and BIPM definitions.
• UK sizing follows the US closely but sits about 0.5 to 1 size lower for men.

All formulas trace back to the same physical length, which is why centimeters act as the neutral translation layer.

UK and US shoe sizes share the same one-third-inch increment but start from a different baseline, so UK men's sizes run about 0.5 to 1 size smaller than US men's (US 10 = UK 9.5).

For women the gap widens to roughly 2 sizes, since US women's sizes already carry a large offset from the men's scale (US women's 8 = UK 6). The UK system is used across Britain, Ireland, Australia, and New Zealand.

Because both systems anchor to foot length, converting through centimeters or the ISO 9407 Mondopoint length avoids the compounding rounding errors that appear when chaining approximate offsets.

To convert a men's shoe size to the US women's equivalent, add 1.5 sizes; to go from women's to men's, subtract 1.5 (a US men's 8 equals a US women's 9.5).

Both scales map to the same foot length, so the 1.5-size offset simply reflects the different starting points chosen for each scale in the US Brannock system.

Width usually differs too, with women's lasts running narrower (B width) than men's (D width). The European system avoids this entirely because it is unisex under the Paris Point standard, meaning a EU 41 denotes the same length regardless of gender.

Children's shoe sizes use a scale separate from adults, which is the biggest source of conversion errors.

In the US and UK, kids' sizes run from 0 (newborn) up to 13, then reset to 1 as adult sizing begins, so a kids' 13 is smaller than a kids' 1 that follows it. EU sizing runs continuously from about 16 for infants up through the adult range, avoiding the reset. The Japanese system stays consistent for all ages because it always equals foot length in centimeters, matching the ISO 9407 Mondopoint principle.

Because children's feet grow quickly, remeasuring every few months is more reliable than converting from an old size.

Shoe size conversion matters most for international online shopping, where a listing may show only EU, UK, or JP sizing. Buyers ordering from European, British, or Japanese retailers use conversion to avoid returns, which run high for footwear precisely because sizing systems differ.

Travelers purchasing shoes abroad, gift-givers who only know a size in one system, and resellers reconciling inventory across marketplaces all rely on accurate cross-system mapping.

Manufacturers and retailers reference the ISO 9407 Mondopoint standard so their charts trace to a common foot-length definition, and the underlying centimeter measurements are grounded in the SI unit of length maintained by BIPM and NIST.

• The most common mistake is applying a single fixed offset across the entire range: because US sizes step by 8.47 mm and EU sizes by 6.67 mm, the difference between them shifts as sizes grow, so US-plus-33 only approximates EU.
• Another error is ignoring the men's-versus-women's 1.5-size gap, which flips results by a full size and a half.
• Confusing kids' and adult scales, especially near the US/UK reset at 13, produces large errors.
• Finally, assuming brand sizing is identical to the standard chart ignores last variation.

When in doubt, convert through foot length in centimeters, the neutral base defined by the SI and the ISO 9407 Mondopoint system.

Every shoe sizing system ultimately encodes the same physical quantity: foot length.

Centimeters work as the universal translation layer because the centimeter is a defined SI unit maintained by the BIPM through the International System of Units, with the inch fixed at exactly 2.54 cm per NIST.

Japanese sizing already equals foot length in centimeters, European Paris Points convert directly from centimeters, and the US Brannock scale derives from inches, which convert exactly to centimeters.

This is why the ISO 9407 Mondopoint standard expresses shoe size as foot length in millimeters — converting through length rather than chaining approximate offsets gives the most accurate cross-system result.