What Size Shoes Should I Buy for a Child With Orthotics?

An orthotic device adds volume inside the shoe. It raises the foot, takes up depth, and reduces the internal space available. A shoe that fits perfectly without an orthotic can end up too tight, too shallow, or impossible to fasten once the device is in place.

This means you'll almost always need to buy a larger size than your child's measured foot length suggests. How much larger depends on the type of device.

The amount of extra room your child needs depends on the thickness and profile of the orthotic device. Use the following table as a starting point:

Orthotic Type	How Much Bigger
Thin over-the-counter insole	Half a size up
Standard custom orthotic	One full size up
Thick or highly contoured custom orthotic	One to one-and-a-half sizes up
AFO (ankle-foot orthosis)	At least one full size up, sometimes more

These are starting points, not hard rules. The only reliable way to confirm the size is to bring the orthotic to the shop and have your child try the shoe with the device in place.

If your child wears an orthotic on only one foot, size for the foot with the orthotic. That foot needs the extra room, and both shoes come from the same pair.

On the non-orthotic foot, adjust the lacing or Velcro to snug the shoe more tightly around the instep. This compensates for the slight extra room on that side.

If the size difference is more than half a size, ask about split-size purchasing at specialist children's shoe retailers. Some will sell two different sizes as a pair, which can make a real difference to comfort.

Going up a size to accommodate the orthotic can sometimes cause heel slip, where the foot lifts out of the shoe at the back with each step. It's uncomfortable, causes blisters, and stops the orthotic working properly. To reduce it:

• Choose shoes with a well-padded heel collar: the padding around the top of the heel cup grips the foot and reduces movement.
• Check for firm heel counters: squeeze the back of the shoe between your thumb and finger. It should resist compression and hold its shape. I call this the squeeze test, and it's one of the most important checks you can do.
• Use laces or Velcro to snug the instep: the fastening across the midfoot is what locks the heel down into the shoe. Tighten it enough to prevent lift without restricting circulation.

When measuring your child's feet for orthotic-compatible shoes, follow these steps:

• Measure with the orthotic inside the sock. Your child should be wearing the socks they'll normally wear with the shoes, and the orthotic should be in place under the foot.
• Measure with full weight on both feet. Your child should be standing, not sitting. Feet spread under body weight, and you need to capture that fuller measurement.
• Measure both feet. It's common for children's feet to be slightly different sizes. Always size for the larger foot (or the foot with the orthotic if only one foot is affected).
• Bring the orthotics to specialist appointments. If you're having your child fitted at a specialist retailer, the fitter will need the device to assess fit properly.

Children's feet grow roughly two sizes per year between the ages of 3 and 10. This growth happens in spurts rather than gradually, so shoes that fit well today can be too small within a few weeks.

For young children during peak growth years, check the fit monthly. It takes two minutes. With the orthotic in place, press your thumb above the big toe while your child is standing. There should be about a thumb's width of space between the longest toe and the end of the shoe.

If the shoes are getting tight, don't wait. Shoes that are too small stop the orthotic sitting correctly and can cause pain, blisters, and pressure injuries.

Should I buy the current size or the next size up to allow for growth?

With the orthotic in place, aim for about a thumb's width of growing room between the longest toe and the end of the shoe. That gives some room for growth without the shoe being so large the foot slides around. More growing room than that increases the risk of tripping and stops the orthotic sitting where it should.

My child's orthotic is very thick and I can't find shoes that fit. What should I do?

Ask your child's orthotist for a referral to a specialist paediatric fitting service. These services stock extra-depth shoes designed for thicker devices and AFOs. Read our guide on where to buy children's orthotic shoes in the UK for more options.

Can I rely on online size charts?

They're a useful starting point, but they can't account for the volume added by your child's specific orthotic device. Always try the shoe with the orthotic in place before committing, whether that means buying from a physical shop or ordering online with a returns policy.

My child has just gone up a shoe size. Do the orthotics still fit?

Not necessarily. If your child's foot has grown a lot, the orthotic may no longer be positioned correctly relative to the arch, heel, and forefoot. Contact the orthotics department to discuss whether the device needs reviewing or replacing.

Looking for the adult version of this guide? Read What Shoe Size Should I Buy With Orthotics?

Browse our full Children's Orthotic Shoe Buyer Guide