Determination of percent ideal body weight for a 9-month-old male who weighs 7.6 kg and is 70 cm long

To determine ideal body weight (IBW), plot the child's length on the length curve (point A) and the weight on the weight curve (point B). Determine the child's length percentile (in this example, 25^th). Draw a vertical line from the length point to the same percentile curve for weight (point C). Draw a horizontal line to the weight scale to determine ideal body weight (point D). Percent IBW = actual weight/IBW × 100. In this example, IBW = 8.6 kg, and percent IBW = 88%.