How to Measure Foot Length and Width — Accurately at Home with a Sheet of Paper
How to measure foot length and foot width and girth at home — the starting point for shoe sizes — plus common mistakes and how to turn your measurements into a size.
The surest way to choose a shoe size is to measure your foot length yourself. Korean mm sizes, Japanese cm sizes and the international Mondopoint standard are all based on foot length, so with one accurate foot length you can move to any other country's size.
What you need
- One sheet of A4 paper (anything big enough to place against a wall)
- A pencil or pen (the finer the better)
- A ruler or tape measure
- The socks you usually wear with that kind of shoe
When to measure
Feet swell slightly over the course of the day. Measuring in the afternoon or evening, after standing or walking for a while, is closest to how your feet are when you actually wear shoes. For athletic shoes, measuring right after exercise is also a good idea.
Measuring foot length
- Put the paper on the floor with one short edge pressed flush against a wall.
- Wearing socks, stand on the paper with your heel against the wall. Spread your weight evenly over both feet (measuring while seated makes the foot spread less and gives a shorter result).
- Have someone hold a pen upright and mark the tip of your longest toe. For many people the second toe is longer than the big toe.
- Measure from the wall (the edge of the paper) to the mark in mm.
- Measure the other foot the same way and use the longer of the two as your foot length.
If the pen is held at an angle, the line is pushed outward around the foot and the result comes out 3–5 mm longer than it really is. If you measure alone, stand a book upright against the front of your toes and measure the distance to the book for an accurate result.
Measuring foot width
Foot width is measured in two ways.
- Foot width: standing on the paper, mark the most prominent points of the bone at the base of the big toe (head of the first metatarsal) and the bone at the base of the little toe (head of the fifth metatarsal), then measure the straight-line distance between the two points.
- Ball girth: wrap a tape measure once around the foot so it passes through the same two points. The width grades of Japan's JIS shoe standard (E, 2E, 3E, 4E) are based on this girth.
The international Mondopoint standard (ISO 9407) defines a way to label shoes with two numbers, ‘foot length/foot width’ (e.g. 265/100). If you also enter your foot width in the converter, it shows your size in this format.
Turning your measurement into a size
Korean shoe sizes state foot length in 5 mm steps. If your foot is 253 mm long, 255 is the reference size. On top of that, add room depending on the type of shoe.
| Shoe | Typical choice |
|---|---|
| Running and walking shoes | A size that leaves about 1 cm of room at the toes |
| Dress shoes and loafers | A size that nearly matches your foot (allowing for leather stretching) |
| Hiking boots | Based on a measurement taken in thick socks, with enough room that your toes don't touch on descents |
| Children's shoes | About 1 cm of room, remeasured every two to three months |
The allowances above are only widely used general guidelines. Every brand and model is designed differently, so make the final decision from the brand's size chart and how the shoe actually feels.
Common mistakes
- Trusting the size of the shoes you currently wear: often those shoes don't fit and you have simply gotten used to them.
- Measuring only one foot: it is common for the two feet to differ by a few mm.
- Measuring in the morning while seated: this gives a shorter result than standing in the evening.
- Solving a width problem with length: if you go up half a size because the ball is pinched, your foot slides forward and your heel lifts. Looking for a wide model is better.
When to see a professional
If you have foot pain, or one foot is unusually uncomfortable because of a bunion (hallux valgus), flat feet or similar, the problem may not be the size. This article only explains how to take measurements and does not replace medical judgment. If needed, consult a specialist shoe store or a medical professional.
Size systems are approximate correspondences based on national standards and industry practice, and can differ by half to one size depending on brand, product and fabric. Always check the brand's own size chart before buying.