Percentile chartsSpec 2.7
A percentile chart is used to monitor the growth of a baby or child. It shows curves for the measurements of a large number of children of the same age and sex, such as mass. A child's measurement is plotted on the chart.
- The 50th percentile line means 50% of children have a lower value and 50% have a higher value.
- A child on the 25th percentile has a value higher than 25% of children and lower than 75% of children.
- Plotting a child's measurements over time shows whether they follow a curve or move across to a different one. A large change may need to be investigated.
The chart is a graph. Use it to turn a number into a percentile, or the reverse.
percentage change = (change in mass ÷ original mass) × 100
Percentage gain in mass
A baby has a mass of 3.2 kg at birth and 4.0 kg at 8 weeks. Calculate the percentage gain in mass.
- change in mass = 4.0 − 3.2 = 0.8 kg
- percentage gain = 0.8 ÷ 3.2 × 100
Answer: 25%