A5.2 Calculating a child’s weight-for-length or height

Tables A5.2.1 and A5.2.2 give the WHO normalized reference weight-for-length (45–110 cm) and A5.2.3 and A5.2.4 weight- for-height (65–120 cm), by sex.

The interpretation of a fixed percentage of the median value varies by age and height, and generally the two scales cannot be compared. The approximate percentage of the median values for –1 and –2 SD are 90% and 80% of the median, respectively.1

‘Length’ in most cases is measured for a child < 85 cm, and ‘height’ for a child ≥ 85 cm. Recumbent length is on average 0.5 cm greater than standing height, although the difference is of no importance for the individual child. A correction may be made by deducting 0.5 cm from all lengths > 84.9 cm if standing height cannot be measured.

In the tables:


  • Locate the appropriate table for boys or girls.

  • Locate the row containing the child’s length in the left column.

  • Note where the child’s weight lies with respect to the lengths recorded in this row.

  • Look up the column to read the weight-for-length of the child.

Example 1: Boy: length 61 cm, weight 5.3 kg. His weight-for-length is –2 SD.

Example 2: Girl: length 67 cm, weight 4.3 kg. Her weight-for-length is < –3SD.

Follow this link to the WHO Simplified Field Table of Weight-for-Length for Boys aged 0 - 2 years.  This is downloadable as a printable PDF.

Follow this link to the WHO Simplified Field Table of Weight-for-Length for Girls, aged 0 - 2 years.  This is downloadable as a printable PDF.