Weight-for-length for girls at 89 cm

At a length of 89 cm, the median weight for girls on the WHO Child Growth Standards is 12.2 kg (26 lb 15 oz): half of girls of this length weigh less and half more. The middle half of girls, from the 25th to the 75th percentile, falls between 11.5 and 13.0 kg, a spread of 1.47 kg. The outer lines of the chart, the 2nd and 98th percentiles, sit at 10.3 and 14.7 kg.

At 87 cm the median weight is 11.7 kg, so 2 cm of extra length goes with about 0.50 kg more weight at the median. At 91 cm it is 12.7 kg. Weight-for-length compares a child's weight with other children of the same length, whatever their age, which is why it can read differently from weight-for-age for a long or a short baby.

For boys at a length of 89 cm the median is 12.5 kg, 0.26 kg more than for girls, which is why the charts are drawn separately by sex.

On the older CDC 2000 weight-for-length charts, which some clinics and websites still use before age 2, the median at a length of 89 cm is 12.6 kg. A girl exactly on the WHO median would read as about the 36th percentile there, one reason two charts can give different answers for the same weight.

Reading the table: a girl at a length of 89 cm who weighs 12.7 kg is at about the 67th percentile, meaning that out of 100 girls of that length, about 67 weigh less.