This measurement is the length of the bottom sole of the shoes. (for instance if your little one’s feet measured 4.5″ from heel to the big toe, I recommend to get the 6-12 mos size).

0-3 mos: 4 inches in length
3-6 mos: 4.5 inches in length
6-12 mos: 5 inches in length
12-18 mos: 5.5 inches in length

Also you can tell me the exact measurement of your little one’s feet from heel to the big toe.

If you forgot to let me know what’s the shoes size that you want, feel free to email me at info@babysoftshoes.com.