Running shoe size converter

The conversion charts

Typical running shoe conversions - most major running brands (Nike, Asics, New Balance, Brooks, Hoka) label within half a size of these. The centimetre column is the shoe's fitting length, not your foot length: pick a shoe about 1 cm longer than your measured foot.

Men's running shoes

Women's running shoes

How to measure your feet properly

• Evening, not morning. Feet swell through the day - size for their biggest.
• In your running socks, standing with full weight on the foot.
• Heel to a wall, on paper - mark the tip of your longest toe (not always the big toe).
• Measure both feet and use the longer one. Most people's feet differ.
• Add about 1 cm of toe room for running - a thumb's width at the front of the shoe.

Brand fit notes

• Nike - tends to run narrow and slightly short; many runners go up half a size.
• Asics / Brooks / New Balance - closest to true-to-size for most feet; several models come in width fittings.
• Hoka - true to size in length, mid-width; some models feel snug across the midfoot.
• Altra / Topo - wide, foot-shaped toe boxes; the same labelled size feels roomier.
• Adidas - length runs close to true; fits narrower in the heel.

These are tendencies, not guarantees - lasts change between models within the same brand. Where a brand publishes a centimetre chart for a specific shoe, trust that over everything.

FAQs

Should running shoes be a size bigger?

Half a size to a full size bigger than your casual shoes for most people. Feet swell and slide on the run - about 1 cm of space in front of your longest toe is the aim.

Why do my Nikes and Asics differ in the same size?

Labelled size systems are only loosely standardised, and each brand builds shoes around its own last. Length differences are small; width and volume differences are big.

What's the cm size on the box?

Most running brands print a CM (or JP) value - that's the shoe's fitting length. It's the most reliable number for comparing across brands.