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First Walker | Sizes 3 - 6
Crawling and First Steps | 9 - 18 Months
Foot: Bones form together and fatty pads minimize
Shoe Needs:
Flexible and lightweight
Outsole with added traction
Roomy toe box for healthy foot development
Wide openings with secure closures
Toddler | Sizes 4 - 9
Walking | 18 Months - 3 Years
Foot: Cartilage in foot begins to harden into bones
Shoe Needs:
Flexible and lightweight
Outsole needs ground traction for newly mobile child
Ample toe box room for development and movement
Some toe protection
Preschool* | Sizes 9.5 - 13.5
Running, Highly Mobile | 3 - 5+ Years
Foot: Bones fuse, fat tissue disappears and arch begins to form
Shoe Needs:
Flexible and lightweight
Traction to accommodate highly mobile child
Durability for active play
Wide openings with secure clsoures
*Select styles available in Grade School sizes 1Y - 4Y
Download our Printable Sizing Guide here.
| See Kai Run Sizing Guide This chart has acommodated for growing room. If the foot measurement lands in between, order a size up. | ||
|---|---|---|
| Crib | ||
| Length | Age (approx.) | Size |
| up to 9.7cm (3 7/8") | 0-6 months | Small |
| up to 10.9cm (4 3/8") | 6-12 months | Medium |
| up to 12.1cm (4 3/4") | 12-18 months | Large |
| First Walkers, Toddlers and Big Kids | ||
| If Your Foot Length Is | You Should Buy | |
| CM | Inches | US Size |
| 10.5cm | 4 1/8" | 3 |
| 10.9cm | 4 3/8" | 3.5 |
| 11.3cm | 4 1/2" | 4 |
| 11.7cm | 4 5/8" | 4.5 |
| 12.1cm | 4 3/4" | 5 |
| 12.5cm | 5" | 5.5 |
| 12.9cm | 5 1/8" | 6 |
| 13.4cm | 5 1/4" | 6.5 |
| 13.8cm | 5 1/2" | 7 |
| 14.2cm | 5 5/8" | 7.5 |
| 14.6cm | 5 3/4" | 8 |
| 15.1cm | 6" | 8.5 |
| 15.5cm | 6 1/8" | 9 |
| 15.8cm | 6 1/4" | 9.5 |
| 16.2cm | 6 3/8" | 10 |
| 16.6cm | 6 1/2" | 10.5 |
| 17.1cm | 6 3/4" | 11 |
| 17.5cm | 6 7/8" | 11.5 |
| 17.9cm | 7" | 12 |
| 18.3cm | 7 1/4" | 12.5 |
| 18.7cm | 7 3/8" | 13 |
| 19.1cm | 7 1/2" | 13.5 |
| 19.6cm | 7 3/4" | 1Y |
| 20cm | 7 7/8" | 1.5Y |
| 20.4cm | 8" | 2Y |
| 20.9cm | 8 1/4" | 2.5Y |
| 21.3cm | 8 3/8" | 3Y |
| 21.7cm | 8 1/2" | 3.5Y |
| 22.1cm | 8 5/8" | 4Y |