Neutral Running Shoe Size Guide

Quick answerChoose running-shoe size by measured length, width, sock thickness and swelling—not by your casual-shoe number. Brand sizing and model lasts vary.

Record the measurement before choosing a number

Measure both feet while standing on a firm surface, using the longest toe and the back of the heel. Keep the measuring tool consistent and record the result in millimeters or centimeters. Nike’s measurement instructions provide a practical method using paper and a helper; the larger foot is the useful starting point.

Then consult the chart for the brand and sizing system you are buying. A US number, a UK number and a centimeter label are not interchangeable. Nike also notes that the centimeter size printed on its boxes differs from measured foot length, an easy distinction to miss when ordering online.

Length, width and volume are separate checks

After choosing an initial size, check whether your toes have usable room and whether the heel remains seated. Increasing length can create space, but it may also leave a shoe that is too long while still tight across the forefoot.

Compare a width option when the length seems right but the sides are compressed. If pressure is mainly over the top, upper volume and lacing may be more relevant. The printed size cannot describe all three dimensions of your foot or the shape of a particular model.

Match the fitting to the way you will use the shoe

Wear the socks and any prescribed insert you plan to use. A fitting with a thin casual sock can answer a different question from a run in a thicker sock. Recheck both feet rather than assuming one successful fit represents the pair.

Keep a brief record of the model, version, size and width that worked. It is a useful starting reference when replacing shoes, not a permanent rule across brands or future updates. If your usual number no longer feels right, repeat the measurements before interpreting the change as a cushioning problem.