CM Foot Length To UK Shoe Size Converter
Convert measured foot length in centimetres to an approximate UK shoe size, with adult, child, growth allowance and brand adjustment options.
Measure And Convert
UK Size Result
Shoe size is not a guarantee of fit. Shape, width, socks, orthotics and brand lasts can change the right choice.
Recent Conversions
Direct Conversion Guide
This converter estimates UK shoe size from measured foot length, not from the length of an old shoe. It adds a toe allowance first, converts the adjusted length into inches, then applies the traditional UK barleycorn sizing formula. Adult and child sizes use different offsets, which is why a 16 cm child’s foot and a 26 cm adult foot cannot be converted with the same single table.
Use the result as a starting size for trying shoes or checking a size chart. Brand lasts differ, sports shoes may be sized differently from formal shoes, and children’s shoes need growth room without being loose enough to trip. If the measurement falls between sizes, the rounding option lets you choose the nearest half size, nearest whole size or next size up.
Formula And Steps
Adjusted length in cm = measured foot length + toe allowance in cm
Adjusted length in inches = adjusted length in cm / 2.54
Adult UK size = adjusted length in inches x 3 - 25
Child UK size = adjusted length in inches x 3 - 12
Measure standing
Stand on paper with weight on the foot. Mark heel and longest toe, then measure the distance in centimetres.
Add allowance
Add toe room before converting. Adults may need less extra space than children who are still growing.
Round sensibly
Round to a half size for adult shoes where available. For school shoes, a trained fitting check can be more useful than a number alone.
Adult Foot Length To UK Size Table
| Measured foot length | Approx UK adult size with 10 mm allowance | Best use |
|---|---|---|
| 22.5 cm | UK 3 | Small adult and some older children’s styles. |
| 23.0 cm | UK 4 | Check width and brand chart. |
| 24.0 cm | UK 5 | Often around women’s UK 5 in many charts. |
| 24.7 cm | UK 6 | Try half sizes if available. |
| 25.5 cm | UK 7 | Common adult crossover size. |
| 26.4 cm | UK 8 | Sports shoe brands may differ. |
| 27.2 cm | UK 9 | Check toe room with socks worn for that shoe. |
| 28.0 cm | UK 10 | Wide feet may need a wider fitting, not just longer size. |
| 28.9 cm | UK 11 | Use brand chart for boots. |
| 29.7 cm | UK 12 | Check returns policy for online orders. |
Child Foot Length To UK Size Table
| Measured foot length | Approx UK child size with 10 mm allowance | Fitting note |
|---|---|---|
| 11.5 cm | UK 4 child | Use a proper infant fitting check. |
| 12.3 cm | UK 5 child | Measure both feet. |
| 13.2 cm | UK 6 child | Allow room without heel slip. |
| 14.0 cm | UK 7 child | Good for rough online chart checking. |
| 14.9 cm | UK 8 child | Recheck after growth spurts. |
| 15.7 cm | UK 9 child | School shoes need width as well as length. |
| 16.6 cm | UK 10 child | Use socks normally worn with the shoe. |
| 17.4 cm | UK 11 child | Brand charts vary. |
| 18.3 cm | UK 12 child | Check toe room after walking. |
| 19.1 cm | UK 13 child | Near the move into adult-style sizing. |
Measuring Foot Length Well
Measure near the end of the day, when feet can be slightly larger. Put paper on a hard floor, stand naturally, and keep the pencil upright when marking the heel and longest toe. Measure both feet and use the longer one. If one foot is much longer or wider, choose shoes for the larger foot and use lacing, insoles or width fittings carefully for the smaller foot.
Do not measure the insole of a worn shoe and treat it as foot length. Shoes contain shape, curve and internal space. A shoe that has stretched or compressed can give a misleading number. For children, remeasure regularly because growth can make a previously safe size too short before the upper looks worn out.
Where Size Charts Differ
UK shoe sizing is not a precise medical measurement. Trainers, walking boots, school shoes, safety shoes and formal shoes can all use different lasts. A brand may also recommend more or less toe room than the 10 mm default. That is why the converter includes toe allowance and brand adjustment. If a brand chart gives its own centimetre range, use the brand chart first and this converter as a cross-check.
FAQs
What UK size is 26 cm foot length?
With a 10 mm toe allowance, 26 cm converts to about UK adult 7. If you use no allowance, the result is smaller. Width and brand shape still matter.
Should I measure both feet?
Yes. Use the longer foot for length size. If width differs, look for width fittings rather than only moving up in length.
How much toe allowance should I add?
Adults often use around 5 to 10 mm, while children’s shoes may need growth room. Too much allowance can make the shoe unstable, so check the fit.
Is a UK shoe size the same for men and women?
The UK number system is broadly shared, but brand lasts and style shape can differ. A UK 6 in one brand may not match another brand exactly.
Can I use this for baby shoes?
Use extra care for babies and early walkers. Soft shoes and infant fittings are about more than length, so a professional fitting may be better.
Why does my usual size differ from the result?
Your usual shoes may be from a brand that runs small or large, or you may prefer extra room, thicker socks or a wider fit.
Sources
- International Organization for Standardization. (2019). ISO/TS 19407: Footwear sizing – Conversion of sizing systems. ISO. https://www.iso.org/standard/72856.html
- National Institute of Standards and Technology. (2008). Guide for the Use of the International System of Units (SI), Special Publication 811. NIST. https://www.nist.gov/pml/special-publication-811
- Clarks. (2026). Kids’ shoes size guide. Clarks. https://www.clarks.com/en-gb/kids-size-guide
- Start-Rite Shoes. (2026). Measure and fit children’s shoes. Start-Rite. https://www.startriteshoes.com/pages/measure-and-fit