Weights of children with age

Newborn 3 kg
6 months 6 kg (2x birth wt at 6 mos)
1 yr 10 kg (3x birth wt at 1 yr)
3 yrs 15 kg (odd yrs, add 5 kg until 11 yrs)
5 yrs 20 kg
7 yrs 25 kg
9 yrs 30 kg
11 yrs 35 kg (add 10 kg thereafter)
13 yrs 45 kg
15 yrs 55 kg
17 yrs 65 kg