Printable guide + calculator
The shoe fit checker
Shoe sizes are a label; millimetres are the truth. Print this page, trace both feet with the six steps below, then feed the numbers into the calculator to get the internal shoe length to shop for, with about 12 mm of toe room built in.
Works for any footwear, and matters double for minimalist shoes: a wide toe box only helps when the toes actually reach it uncrushed.
Part 1: paper and pencil
Trace and measure
You need paper, tape, a pen and a ruler or tape measure. Print this page and the steps come with you.
01. Set up in the evening
Feet swell through the day, so trace after a normal day on them. Tape a sheet of paper to a hard floor so it cannot slide; add a second sheet lengthways if your foot is longer than the page.
02. Stand, do not sit
Stand on the paper with your full weight on that foot, knee slightly bent, wearing the socks you would wear in the shoes. Weight-bearing feet are longer and wider than lifted ones.
03. Trace with the pen vertical
Hold a pen or pencil straight up and down, not angled under the foot, and trace all the way around. An angled pen shaves millimetres off every edge.
04. Measure length
Draw a straight line from the back of the heel outline to the tip of the longest toe outline; that is your foot length in millimetres. The longest toe is not always the big toe.
05. Measure width
Measure straight across the widest part of the outline, usually across the ball of the foot.
06. Repeat on the other foot
Nearly everyone has one longer foot. Trace both, and shop for the larger one; the smaller foot can be snugged with lacing, the larger one cannot grow room.
Part 2: the numbers
Turn millimetres into a fit
Enter your trace
Heel to the tip of your LONGEST toe, from the tracing. Use the larger foot; feet differ.
Across the widest part of the ball of the foot.
Your fit
Trace, measure, enter the millimetres, and the numbers to shop with appear here.
Sources
- Foot pain and foot problems NHS, 2024
- Public foot health information Royal College of Podiatry, 2024
Last reviewed: 2026-07-16
New shoes measured. Feet next.
A well-fitting minimal shoe still needs a foot that is ready for it. The self-check tells you in minutes.
Check your feet