Shoe Size Converter (UK/EU/US)

Convert shoe sizes between UK, EU, US (men and women) and centimetres.

Source: NHS — Choosing the right shoes

By Konstantin Iakovlev · Founder, Calks.uk

Last updated: April 2026 · Verified against HMRC and GOV.UK 2026/27 rates

How we calculate

Size System

Size

US Men's

US Women's

10.5

Disclaimer

This calculator is provided for informational purposes only and should not be considered as financial or tax advice. All calculations are performed locally in your browser — no personal data is collected or sent to our servers. Rates and thresholds are sourced from HMRC and GOV.UK and are updated for the current tax year. Always verify results with HMRC or consult a qualified professional before making financial decisions.

How It Works

UK shoe sizes use a different scale from US and EU sizes. UK sizes start from 0 for infants and increase in increments of one-third of an inch (8.47 mm). EU sizes follow the Paris point system where each size is 6.67 mm. US sizes are offset from UK sizes by approximately 1 for men and 2 for women.

This converter handles men's, women's and children's sizes across UK, US and EU systems. Half sizes are supported. It also shows the corresponding foot length in centimetres for each size, which is the most accurate way to find your correct size across systems.

UK, EU, US shoe size conversions. Approximate adult: UK 6 = EU 39-40 = US M 7 = US W 8.5 = JP 25cm. UK 7 = EU 40-41 = US M 8 = US W 9.5 = JP 26cm. UK 8 = EU 41-42 = US M 9 = US W 10.5 = JP 27cm. UK 9 = EU 42-43 = US M 10 = US W 11.5 = JP 28cm. Each UK whole size = 8.5mm (1/3 inch). Each US size: same. EU sizes: ~6.67mm per size (Paris point = 2/3 cm).

How to measure your foot. Stand on paper barefoot at end of day (feet swell). Mark heel and longest toe. Measure heel-to-toe in mm. UK size = (length mm − 23.85) ÷ 8.46. EU size = length × 1.5 (in cm). Width: measure across widest part of ball. UK widths: E (medium), F (wide), G (extra wide), H (men 4E+ equivalent). Most high-street shoes: E (medium). Clarks, Hotter offer F-H widths for wider feet.

Trainers/sneakers — sizing differences. Trainers typically fit smaller than formal shoes — most brands recommend going up ½ size. Nike runs slim (size up ½). Adidas Stan Smith true to size. New Balance runs wide (size down). Converse runs 1 full size large (size down 1). Running shoes need 1cm toe clearance for downhill — half size larger than walking. Football boots fit tight (control). Cycling shoes very tight.

Children's shoe growth. Children grow 2 shoe sizes/year aged 0-3; 1 size/year aged 4-7; then slower. School-age: get measured every 8-12 weeks at Clarks/Start-Rite/similar. Toe room: 1cm space at front (thumb width). Don't pass down well-worn shoes — moulded insoles match original wearer. Sample children's: age 1 UK 4; age 3 UK 8; age 5 UK 11; age 7 UK 1 (adult range begins). Free children's foot health checks at most UK shoe shops.

Specialist shoe sizing. Walking boots: half size up from standard for thicker socks + foot expansion on long walks. Ski boots: very tight initially (mould to foot); rented sometimes inexact. Football boots: tight for control — often go down ½ from trainer size. Steel-toe safety boots: full size up (thicker construction). Wedding/formal: regular size — wear thin socks/stockings. Bunions, hammer toes: wide-fit shoes (UK E-H widths) — Clarks Wallabees, Hotter, Footglove.

Example: UK men's size 9

UK 9 = US 10
UK 9 = EU 43
Foot length: approx. 27.5 cm

Source: NHS — Choosing the right shoes

Frequently Asked Questions

UK, EU, US and Japan shoe size conversions.: Approximate adult conversions — UK 7 = EU 41 = US Men 8 = US Women 9.5 = JP 26cm. UK 8 = EU 42 = US M 9 = US W 10.5 = JP 27cm. Each UK whole size = 8.5mm (1/3 inch); each US size = same. EU sizes increase ~6.67mm per size (Paris point = 2/3cm). Children: UK Children 13 ≈ UK Adult 1 ≈ EU 31-32. Always check the brand — Italian shoes (Gucci, Prada) often run small; American athletic brands (Nike, Adidas) run true.
How to measure foot length correctly.: Stand on a sheet of paper barefoot at end of day (feet swell). Mark heel and longest toe. Measure heel-to-toe in mm. UK size = (length in mm − 23.85) ÷ 8.46. EU size = length × 1.5 (in cm). Width: measure across widest part of ball. UK widths E (medium), F (wide), G (extra wide), H (men 4E+ equivalent). Most high-street shoes are E (medium); Clarks, Hotter offer F-H widths for wider feet.
Trainer/sneaker sizing differences from formal shoes.: Trainers fit smaller than formal shoes — most brands recommend half-size up. Nike runs slim (size up half); Adidas Stan Smith true to size; New Balance runs wide (consider going down); Converse runs 1 full size large (size down). Running shoes need 1cm toe clearance for downhill running — half size larger than walking shoes. Football boots fit tight intentionally (control). Cycling shoes very tight, formal lasts.
Children's shoe size growth rates.: Average UK child grows 2 shoe sizes per year aged 0-3, 1 size per year aged 4-7, then slower. School-age (5+): get measured every 8-12 weeks at Clarks, Start-Rite or similar with gauges. Toe room: 1cm space at front when standing (about a thumb's width). Don't pass down well-worn shoes — moulded insoles match the original wearer's foot. Sample children's: age 1 = UK 4; age 3 = UK 8; age 5 = UK 11; age 7 = UK 1 (adult range begins around UK 1).