The mid parental height is calculated in males, by adding 7cm to the mean of parental heights; in females by subtracting 7cm. This gives the height expected at 18 years for the child, and this can be plotted on the percentile chart to predict the child's height at the appropriate age.

How do you plot mid parental height on a growth chart?

Calculating the mid-parental centile

If not available, use reported heights. Mark their heights on the relevant Mother and Father scales. Join the two points with a line between them. The mid parental centile is where this line crosses the centile line in the middle.

How accurate is mid parental height?

Based on final height regression coefficients to midparental height, the estimated heritability value is 0.75-0.78 in cm or 0.55-0.60 in SDS. The 95% CIs of the regression coefficients of final height by father's height and mother's height are approximately the same in any group.