How do I convert my shoe size?
Pick the scale your size is in and enter the size. The converter shows the same shoe in US men's, US women's, UK, and EU sizes, and the foot length it fits.
- Converted size
- US men's 6.5
US women's 8 is US men's 6.5.
- US men's
- 6.5
- US women's
- 8
- UK
- 5.5
- EU
- 38.5
- Foot length (cm)
- 24.1
- Foot length (in)
- 9.5
- Mondopoint (mm)
- 245
Converted size: US men's 6.5. US women's 8 is US men's 6.5.
How to calculate
Converts an adult shoe size between US women's, US men's, UK, and EU sizes and foot length, from the standard size formulas.
Example with the default inputs (Size system US women's, Size 8, US women's scale Men's + 1½ (common)): US women's 8 is US men's 6.5.
Method: foot length L (mm) from your size; UK = 3 × L ÷ 25.4 − 23; US men’s = UK + 1; US women’s = US men’s + 1½; EU = 3 × L ÷ 20 + 2
- Adult sizes only: UK 0 to 20. Children’s sizes use other zero points.
- UK sizes count barleycorns (1/3 inch) and EU sizes count Paris points (2/3 cm) of shoe last length. The last is taken as 2 sizes longer than the foot, as in ISO/TS 19407.
- US men's = UK + 1. US women's = US men's + 1½ on the common scale, or + 1 on the FIA scale.
- Every size is rounded up to the next half size, and Mondopoint up to the next 5 mm, because a shoe a little too big fits and one too small does not.
- Brands and countries differ by up to a size. Check the brand’s own chart, or measure your foot and compare foot lengths.
Worked examples
Each example is checked against the calculator on every build.
- Size system US women's, Size 8, US women's scale Men's + 1½ (common) gives Converted size US men's 6.5, US men's 6.5, UK 5.5, EU 38.5, Foot length (cm) 24.13, Foot length (in) 9.5, Mondopoint (mm) 245.Source: ISO/TS 19407:2015 sizing conversion (https://www.iso.org/standard/62349.html)
- Size system US men's, Size 10, US women's scale Men's + 1½ (common) gives Converted size US women's 11.5, UK 9, EU 43, Foot length (cm) 27.093333, Mondopoint (mm) 275.
- Size system EU, Size 42, US women's scale Men's + 1½ (common) gives US men's 9.5, US women's 11, UK 8.5, EU 42, Foot length (cm) 26.666667, Mondopoint (mm) 270.
- Size system US women's, Size 8, US women's scale Men's + 1 (FIA) gives US men's 7, UK 6, EU 39, Mondopoint (mm) 250.
- Size system Foot length (cm), Size 24, US women's scale Men's + 1½ (common) gives US men's 6.5, US women's 8, UK 5.5, EU 38, Mondopoint (mm) 240.
How it works
Every size scale measures the same thing in its own steps: the length of the shoe's last, which is a little longer than the foot. The converter turns your size into the foot length it fits, L in millimetres, then into every scale.
From your size to the foot length L (mm):
- UK: L = 25.4 ÷ 3 × (UK + 23). A UK size step is one barleycorn, 1/3 inch.
- US men's: UK = US men's − 1, then as UK.
- US women's: UK = US women's − 2½ on the common scale (− 2 on the FIA scale), then as UK.
- EU: L = 20 ÷ 3 × (EU − 2). An EU size step is one Paris point, 2/3 cm.
- Foot length in cm: L = cm × 10.
From the foot length to every scale:
- UK = 3 × L ÷ 25.4 − 23
- US men's = UK + 1
- US women's = US men's + 1½ (common) or + 1 (FIA)
- EU = 3 × L ÷ 20 + 2
- Mondopoint = L, in mm
- Foot length = L ÷ 10 cm, or L ÷ 25.4 inches
The UK and EU formulas are the ISO/TS 19407 ones: each takes the last as 2 sizes longer than the foot.
Rounding
Shoes come in half sizes, so the US, UK, and EU sizes are rounded up to the next half size (a size that is already a half size stays). Mondopoint is rounded up to the next 5 mm. ISO/TS 19407 also rounds to the larger size, because a shoe a little too big fits and one too small does not. The foot length is not rounded.
Assumptions
- Adult sizes only: UK 0 to UK 20, a foot length of 194.7 mm to 364.1 mm. Other inputs have no answer. Children's sizes start from other zero points.
- The common US women's scale is the default. Pick the FIA scale under More options.
- Brands differ. These are the standard conversions, not a brand's chart.
Worked examples by hand
US women's 8 (common scale). UK = 8 − 2.5 = 5.5, so US men's = 6.5. L = 25.4 ÷ 3 × (5.5 + 23) = 25.4 ÷ 3 × 28.5 = 241.3 mm, which is 24.1 cm or 9.5 in. EU = 3 × 241.3 ÷ 20 + 2 = 38.195, rounded up to 38.5. Mondopoint: 241.3 mm rounded up to 245.
US men's 10. UK = 9, US women's = 10 + 1.5 = 11.5. L = 25.4 ÷ 3 × 32 = 270.93 mm (27.09 cm). EU = 3 × 270.93 ÷ 20 + 2 = 42.64, rounded up to 43. Mondopoint 275.
EU 42. L = 20 ÷ 3 × 40 = 266.67 mm. UK = 3 × 266.67 ÷ 25.4 − 23 = 8.496, rounded up to 8.5; US men's 9.496 rounds up to 9.5; US women's 10.996 rounds up to 11. Mondopoint 270.
US women's 8 (FIA scale). UK = 8 − 2 = 6, US men's = 7. L = 25.4 ÷ 3 × 29 = 245.53 mm. EU = 38.83, rounded up to 39. Mondopoint 250.
A 24 cm foot. L = 240 mm. UK = 3 × 240 ÷ 25.4 − 23 = 5.35, rounded up to 5.5; US men's 6.5; US women's 8; EU = 3 × 240 ÷ 20 + 2 = 38. Mondopoint 240.
Other questions people ask
How do I convert women's to men's shoe sizes?
Subtract 1½. A US women's 8 is a US men's 6.5, and a women's 10 is a men's 8.5. Some makers use the older FIA scale, where the gap is 1 size; pick it under More options.
How do I convert men's to women's shoe sizes?
Add 1½. A US men's 9 is a US women's 10.5. On the FIA scale, add 1.
How do UK and US sizes compare?
A US men's size is 1 more than the UK size, and a US women's size is 2½ more (2 on the FIA scale). So a UK 7 is a US men's 8 and a US women's 9.5.
How are EU sizes worked out?
An EU size counts Paris points (2/3 cm) of shoe length. With the usual allowance of 2 sizes over the foot, EU size = 3 × foot length in mm ÷ 20 + 2. A 26 cm foot is EU 41.
Why does my size differ between brands?
The scales are old conventions, not a strict standard, and each maker picks its own lasts and allowances. Sizes can differ by half a size or more. For the best fit, measure your foot and use the brand's own chart.
How do I measure my foot length?
Stand on a sheet of paper with your heel against a wall, mark the tip of your longest toe, and measure from the wall to the mark. Measure both feet in the evening and use the longer one.