12 Month Baby Weight & Height: WHO Growth Standards & Percentiles
Reviewed by Dr Abhas Gupta, MBBS, MD, DNB (Paediatrics), PDCC (Paediatric Rheumatology) • About Dr Abhas Gupta (Bio) • Last reviewed: 16 October 2026
Compare your 12-month-old baby's weight and length against official World Health Organization (WHO) international growth charts. Calculate exact Z-scores, track monthly velocity, and plot their developmental curve channel.
What's normal at 12 months
During the second half of the first year, active sitting, crawling, and pulling to stand burn substantial calories. Growth channels steady as complementary solid foods are introduced alongside breast milk.
Expected monthly weight gain: 350 to 450 grams per month (approx. 10–15 grams per day)
WHO Growth Standards for 12 Month Olds
According to World Health Organization (WHO) multicentre growth standards, benchmarks for 12-month-old infants are:
- Boys Median Weight: 9.6 kg (3rd centile: 7.8 kg, 97th centile: 11.8 kg)
- Girls Median Weight: 8.9 kg (3rd centile: 7.1 kg, 97th centile: 11.3 kg)
- Boys Median Length: 75.7 cm (3rd centile: 71.3 cm, 97th centile: 80.2 cm)
- Girls Median Length: 74 cm (3rd centile: 69.2 cm, 97th centile: 78.9 cm)
Normal range at 12 months
| Centile | Boys Weight (kg) | Girls Weight (kg) | Boys Length (cm) | Girls Length (cm) |
|---|---|---|---|---|
| 3rd | 7.8 | 7.1 | 71.3 | 69.2 |
| 50th (Median) | 9.6 | 8.9 | 75.7 | 74 |
| 97th | 11.8 | 11.3 | 80.2 | 78.9 |
Vaccines due at 12 months
12 Months visit: Hepatitis A dose 1, JE dose 1 (only if advised in your area).
Feeding stage at 12 months
Toddler Family Table Meals (12–24 Months): Full transition to wholesome family meals with mild spices, legumes, seasonal vegetables, whole animal milk in an open cup, and healthy fats.
Calculate Your 12 Month Old's Percentile
Frequently Asked Questions for 12 Month Olds
Is 7.1–11.3 kg (girls) or 7.8–11.8 kg (boys) normal for a 12 month old baby?
Yes. According to official World Health Organization (WHO) Child Growth Standards, the healthy normal range (3rd to 97th percentile) for a 12-month-old boy is 7.8–11.8 kg (median: 9.6 kg), and for a 12-month-old girl is 7.1–11.3 kg (median: 8.9 kg). A baby tracking steadily along any channel within this window is developing normally.
How much weight should a 12 month old gain in a month?
According to WHO growth velocity benchmarks, a healthy 12-month-old baby typically gains about 350 to 450 grams per month (approx. 10–15 grams per day). Weight gain velocity slows naturally across the first year as mobility and activity increase.
When should I worry about my 12 month old's weight?
Consult your pediatrician if your baby's weight sits below the 3rd percentile (7.8 kg for boys, 7.1 kg for girls), crosses two major percentile lines downward over consecutive months, or shows zero weight gain across two consecutive clinical checkups.