The first thing to check in a child's shoe isn't the sole or the toe box: it's the size. It's the only criterion with a measured dose-response relationship, and it's where most children's footwear falls short. In a study in Seville of 505 children aged 3 to 12, 72.5% were wearing shoes that were too short and 66.7% shoes that were too narrow. A third were wearing shoes shorter than their own feet.
After size come seven checks you can do in under a minute: a wide toe box, a sole that bends and twists, a soft heel counter, heel and toe at the same height, low weight, a flat removable insole, and a fastening that genuinely adjusts. If a shoe fails on size or on the toe box, it isn't right for your little one, whatever the label says.
In this guide
- Start here: the size
- The seven shoe checks
- Common mistakes when buying children's shoes
- Signs that their current shoes aren't right
- Checklist to keep on your phone
- Frequently asked questions
Start here: the size
Why it comes first
An Austrian study of 858 preschoolers measured something that is almost never measured: how much the risk rises for each size too small. The risk of big toe deviation increased by 17% with one size too small, 37% with two and 61% with three (Klein et al., BMC Musculoskeletal Disorders, 2009). The authors themselves present it as the first systematic empirical evidence that short footwear is a risk to foot development.
And there's an added problem: the size on the box isn't reliable. Of 316 pairs analysed in another study, only 3.8% were correctly labelled, and 95.3% measured less on the inside than their stated size (Kinz et al., 2015). That's why you need to measure the foot and measure the shoe, not trust the number.
How to measure the foot at home
- Put a sheet of paper on the floor, against the wall.
- Your little one stands on it, heel against the wall, with their weight spread across both feet. Sitting down won't do: the foot lengthens when it bears weight.
- With a pencil held upright, mark the longest toe, which isn't always the big toe. More than half of children have a longer big toe, but not all.
- Measure from the edge to the mark. Repeat with the other foot and go with the larger one.
- Measure the width across the toes too. It's the measurement most often forgotten and the one behind most returns.
Take a look at our Feroz size guide, which shows the process in detail.
How to check the shoe
The best method is the insole: take it out, put it on the floor and have your little one stand on it. You can see at a glance whether the toes stick out at the front or spill over the sides. Barefoot shoe insoles are removable precisely for this.
The quick check, with the shoe on: standing with weight on the foot, there should be a finger's width of space at the front, no more, and your index finger should slip in at the heel fairly easily.
At Feroz we work with a margin of 0.8 to 1.2 cm in front of the longest toe. When it drops below 0.5 cm, it's time to change.
And if your little one wears insoles prescribed by a professional, check the size with the insole inside the shoe.
How often to measure, by age
Feet don't grow at a steady rate, and knowing this saves money and upset:
| Age | Rate of change |
|---|---|
| 0 to 15 months | Half a size roughly every 2 months |
| From first steps | Half a size every 3 or 4 months |
| 6 to 12 years | Practically the same size for 6 months |
| From age 7 | Growth picks up again steadily until 16 |
The seven shoe checks
1. The toe box: is there room for the toes to spread?
The wide toe box is where the toes go. In a barefoot shoe it's the widest part of the shoe, because that's what a foot is like: the widest part is the toes, not the instep. Look at the shoe from above. If it narrows towards the tip, the toes have no room to spread as the foot lands.
That children's footwear is too narrow is well documented: 66.7% in the Seville study, and up to 98% in a South African study of children who usually go barefoot, who have wider feet.
2. The sole: does it really bend?
Hold the shoe by the toe and the heel and bring your hands together. It should give easily and bend at the toe area, which is where the foot bends, not in the middle of the sole. Then twist it, as if you were wringing out a cloth.
Footwear measurably reduces movement of the big toe and the ankle, and the stiffer it is, the more it reduces it. What we don't know (and the authors of the meta-analysis that measured it say so explicitly) is what long-term effect that has on development.
3. The heel counter: does the heel give?
The heel counter is the piece that wraps around the heel. The test is simple: press the heel of the shoe with both thumbs. It should fold inwards.
The heel needs stability and support, which come from the fit, not containment, which comes from stiffness. That said, in all honesty: there are no studies in children on stiff heel counters, either for or against. It's a design criterion consistent with "the shoe should get in the way as little as possible", not a health claim.
4. The drop: is the heel higher than the toe?
Drop is the difference in height between heel and toe. Zero drop means the foot rests flat, just as it would barefoot. Put the shoe on the table and look at it side-on at eye level.
The reasoning behind it: the normal load distribution in the foot is roughly 70% on the heel and 30% on the forefoot, and one centimetre of elevation brings it closer to 50-50 in children. It's a mechanical argument, and it's worth knowing that there are no studies on drop in children. We say so because we'd rather you knew.
5. The weight: does it weigh their foot down?
Pick it up and compare it with another shoe in the same size. There's no published ideal weight or paediatric studies on this. What is reasonable is that more weight means more changes in how they walk, and that a little one who is learning lifts their foot many times with little strength.
6. The insole: is it flat, and does it come out?
Flat, thin and removable, with no pre-shaped arches or heel cups. Being removable matters for two practical reasons: it's how you check the size properly, and it's what lets you fit a prescribed insole if a professional recommends one.
On pre-shaped arches, there's something worth knowing: in children without pain, the 2022 Cochrane review concluded that there is no evidence to support the use of insoles. And in an Austrian study, 10% of preschoolers wore insoles and the authors concluded that more than 90% of those treatments were unnecessary.
7. The fastening and the materials
The fastening. It needs to open the instep wide and let you adjust it to the sock and the time of day. Wide hook-and-loop fastening, laces or a buckle. What's best avoided is a shoe that stays on by pressure alone, with no adjustable fastening: to stop it falling off it has to be narrow, and then the shoe is doing the fitting instead of the fastening.
And there's a reason that isn't technical: a fastening your little one can manage alone means autonomy. At nursery they put their shoes on and take them off several times a day, and being able to do it without help makes more difference to their day than any detail of the sole.
The materials. They should be breathable, with soft linings and no seams that rub. Run your hand over the whole inside before you buy: what feels slightly scratchy to you can bother a small foot quite a lot. Many blisters blamed on the shoe actually come from the sock, so check that too: too long and it bunches over the toes, too short and it slides down inside the shoe.
Care. A damp cloth and mild soap. Never in the washing machine, because hot water and detergents damage the materials.
Common mistakes when buying children's shoes
- Trusting the number. Only 3.8% of the pairs in one study were correctly labelled.
- Buying a size up "so they last". A size too big is as unhelpful as a size too small: the big one alters the gait, the small one pinches.
- Measuring with your little one sitting down. A weight-bearing foot is longer.
- Measuring only one foot, or measuring only the length and forgetting the width.
- Shopping first thing in the morning. By the end of the day the foot is slightly more swollen.
- Hand-me-down shoes. Every foot leaves its own imprint and wear, and another child's won't suit yours. It's one of the few things where it's best not to economise.
- Wearing just one pair. Alternating shoes is better than wearing the same ones every day.
- Taking the "barefoot" on the label at face value. It isn't a regulated term.
Signs that their current shoes aren't right
These are signs to review the shoes, not symptoms of anything:
- Red marks on the toes or instep when you take the shoes off
- Overlapping or curled toes when barefoot
- The shoe always loses its shape in the same place
- They take their shoes off as soon as they can
- They tire sooner than usual on walks they used to manage well
- Socks always wearing through at the same toe
When to see a professional, which is a different matter: persistent pain, limping or a change in the way they walk, swelling or redness that doesn't go away, frequent falls, or anything that worries you. That's for a podiatrist or your paediatrician to assess, not an article.
Checklist to keep on your phone
- I've measured both feet standing up, length and width
- There's 0.8 to 1.2 cm in front of the longest toe
- The foot fits the width of the insole without spilling over
- The toe box is the widest part of the shoe
- It bends at the toe area, effortlessly
- It twists in your hand
- The heel counter folds inwards with your thumbs
- Heel and toe at the same height
- It's light compared with another shoe in the same size
- The insole is flat and comes out
- The fastening opens the instep wide and they can manage it themselves
- No seams inside that rub
Frecuently Asked Questions
How do I know if a shoe is foot-friendly for my child?
Start with the size, as that is where most shoes fall short: take out the insole, place it on the floor, and have your child stand on it to check the length and width. Then make sure the toe box is the widest part, that the sole bends at the toes and can twist, that the heel counter gives under pressure from the thumbs, that the heel is not raised, that it is lightweight, that the insole is flat and removable, and that the closure opens wide over the instep.
How much space should there be at the tip of the shoe?
Between 0.8 and 1.2 cm in front of the longest toe, which is approximately the width of one finger. When there is less than 0.5 cm left, it is time to change sizes.
What is a wide toe box?
It is the area of the shoe where the toes go. In barefoot footwear, it is the widest part of the shoe, so that the toes can spread when standing, just as they do barefoot.
What does zero drop mean?
That the heel and the toe are at the same height and the foot lands flat. It is worth knowing that this is a design criterion: there are no studies on the drop of footwear in children.
How do I measure my child's foot at home?
Standing up, with the heel against the wall, on a piece of paper. Mark the longest toe with a pencil held vertically and measure from the edge. Measure both feet for length and width, and go with the larger measurement. Repeat every 2 or 3 months.
Can I trust the size printed on the box?
Not entirely. In an analysis of 316 pairs, only 3.8% were correctly labeled, and 95.3% were shorter on the inside than their size indicated. Measure the foot and check the shoe with the insole.
Are shoes handed down from a sibling suitable?
It is not a good idea. Used footwear carries the imprint and wear of another child's gait, and that affects the foot that inherits it.
What if the school requires a specific shoe?
Almost always, the rule is about color or closure type, not stiffness, and there are flexible options that comply. School shoes are worn for the most hours, so that is where it is most worth insisting.
