How to measure your child’s foot and height at home
Paper, pen, ruler, and a book — then foot length (heel to toe, longer foot wins) and height against a wall. Enter both in WhatSizer for clothing and shoe sizes, growth room, and next-season hints you can share with family.
Watch the walkthrough
Need your kid’s size in minutes? The short video follows the same flow as this guide: measure foot and height, open WhatSizer.com, enter the numbers, get instant recommendations with room to grow, seasonal outlook, and an easy way to share with grandparents.
- Heel-to-toe on paper — use the longer foot
- Height against a wall with a book on the head
- Enter measurements in WhatSizer
- Instant sizes, next-season outlook, share with family
What you’ll need
Paper, a pen, a ruler (or tape measure), a thick hardback book, and your child. A flat wall and hard floor help. For shoes, measure with the socks they usually wear.
Step one: foot length (heel to toe)
Stand on a sheet of paper on a hard floor. Trace around one foot with the pen straight up, or mark heel at the wall and the longest toe on the paper.
Measure the longest line from heel to longest toe. Repeat for the other foot.
Use the longer measurement when you buy one pair — almost everyone has a slightly longer foot, and the shoe should fit that foot comfortably.
Step two: height
Have your child stand straight with heels, bottom, and shoulders lightly touching the wall (barefoot or in thin socks).
Place the flat edge of the book on their head so it touches the wall at a right angle. Mark the wall where the underside of the book meets it.
Measure from the floor straight up to the mark. That is their standing height.
Enter it in WhatSizer
Go to whatsizer.com and open the size tool for your language. Enter foot length and height in the units shown (cm or inches depending on region).
Add optional details (age, gender, weight) if you want — they improve seasonal projections. Submit to see clothing and shoe sizes for your region.
What you get
Instant size recommendations with sensible room to grow so everyday fit stays safe, not floppy.
Forecasts for upcoming seasons so you can shop ahead instead of guessing from last year’s labels.
Share a secure link with grandparents or carers so everyone shops the same numbers — fewer wrong-size gifts.
Why foot length beats guessing a “shoe size”
EU, UK, and US labels are mapped from foot length, but brands differ. Measuring the foot removes most of that guesswork.
Common mistakes
Tracing the foot while sitting — feet spread when standing; measure standing.
Tilting the pen inward so the outline is too small.
Measuring height with shoes on or with slouched posture.
Using months-old numbers without re-measuring after a growth spurt.