Elastic length on each size (waist size, minus 2 inches) if you're unsure on sizing feel free to message me. 
6-12 months 17 inches
12-18 months 17.5 inches
18-24 months 18 inches
2 years 19 inches
3 years 19.5 inches
4 years 20 inches
5 years 20.5 inches
6 years 21 inches