What this calculator does

Children's feet grow quickly, so foot length and growth room matter more than the last size bought. This calculator estimates a starting UK and EU shoe size.

Formula used

The calculator adds growth room to measured foot length, converts the result to centimetres and maps it to approximate children's UK and EU sizes.

How to read the result

Shoes still need a fit check. The heel should hold, toes should have space and the shoe should suit the child's foot width.

Assumptions

  • Uses foot length in millimetres.
  • Adds growth room before estimating size.
  • Brand charts and fitting gauges can differ.

Sources and checks

This calculator uses a standard public formula. Where rules or thresholds can change, source links are listed on the relevant page.

Frequently asked questions

How much growth room should I allow?

Around 10 to 12 mm is a common starting point, but toddlers, school shoes and sport shoes may need different checks.