Shoe Size Calculator
Measure your foot, type the length, and see your size in Nike, Adidas, New Balance and Asics. The calculator uses each brand's own foot-length chart, so you are not guessing from an old pair.
How to use the calculator
- Put a sheet of paper on a hard floor against a wall and stand on it, heel touching the wall.
- Mark the tip of your longest toe and measure from the wall to the mark. Do both feet.
- Enter the longer measurement above. Measure in the evening, wearing the socks you plan to wear.
Need the full method with photos and common mistakes? Read how to measure your feet at home.
Reference chart (men's, standard sizing)
This is the standard chart most US sizing follows (it matches Nike's). For brand-by-brand tables, open the full conversion chart.
| US Men's | UK | EU | Foot length (cm) | Foot length (in) |
|---|---|---|---|---|
| 6 | 5.5 | 38.5 | 24 | 9.45 |
| 6.5 | 6 | 39 | 24.5 | 9.65 |
| 7 | 6 | 40 | 25 | 9.84 |
| 7.5 | 6.5 | 40.5 | 25.5 | 10.04 |
| 8 | 7 | 41 | 26 | 10.24 |
| 8.5 | 7.5 | 42 | 26.5 | 10.43 |
| 9 | 8 | 42.5 | 27 | 10.63 |
| 9.5 | 8.5 | 43 | 27.5 | 10.83 |
| 10 | 9 | 44 | 28 | 11.02 |
| 10.5 | 9.5 | 44.5 | 28.5 | 11.22 |
| 11 | 10 | 45 | 29 | 11.42 |
| 11.5 | 10.5 | 45.5 | 29.5 | 11.61 |
| 12 | 11 | 46 | 30 | 11.81 |
| 12.5 | 11.5 | 47 | 30.5 | 12.01 |
| 13 | 12 | 47.5 | 31 | 12.20 |
| 14 | 13 | 48.5 | 32 | 12.60 |
| 15 | 14 | 49.5 | 33 | 12.99 |
Frequently asked questions
How accurate is a shoe size calculator?
It is as accurate as your measurement. Brands publish the foot length each size is built for, and the calculator matches your length to those charts. Measure both feet in the evening, use the longer one, and you will land on the right size in most cases. Model-specific quirks (a narrow toe box, a thick tongue) still matter, so check the guide for the exact shoe.
Should I round my foot length up or down?
Up. The calculator picks the smallest size whose listed foot length is equal to or longer than yours. Shoes need a little space in front of the toes, so rounding down usually ends with a shoe that pinches by the end of the day.
Why does the calculator give different US sizes for different brands?
Each brand maps sizes to foot length slightly differently. A 27 cm foot can be a US 9 in one brand and a US 9.5 in another. That is exactly why converting by foot length is safer than copying the number from your old pair.
What if I am between two sizes?
For running and training shoes, take the larger size: feet swell during runs. For leather lifestyle sneakers that stretch, many people prefer the smaller one. If your feet are wide, always go with the larger size or look for a wide (2E) version.