Average Length for a 20-Month-Old Girl
The average (50th-percentile) length for a 20-month-old girl is 82.7 cm (32.6 in), based on the WHO Child Growth Standards. Across the healthy range, most girls this age measures between 77.0 cm (30.3 in) and 88.4 cm (34.8 in). (length is measured lying down until age 2)
| Percentile | Metric | Imperial |
|---|---|---|
| 3rd | 77.0 cm | 30.3 in |
| 15th | 79.6 cm | 31.3 in |
| 50th | 82.7 cm | 32.6 in |
| 85th | 85.8 cm | 33.8 in |
| 97th | 88.4 cm | 34.8 in |
What's typical at this age
Growth in length is gradual and steady through the second year. What matters is that your child keeps following their own curve rather than the exact number. Between month 20 and month 21, the median girl grows about 1.0 cm.
A percentile compares your girl to other girls the same age — the 50th is simply the middle. Being above or below it is usually completely normal; a baby who has always tracked the 15th or 85th percentile is typically growing exactly as they should. What pediatricians watch for is a sudden change in the pattern, not the number itself.
See your own baby's percentile
Enter your child's exact weight and height for their personal WHO percentile and growth curve.
Open the Growth Calculator →Percentiles calculated from the WHO Child Growth Standards (2006). For information only — not medical advice. If you're concerned about your child's growth, speak to your pediatrician or health visitor. Full disclaimer.