Measure standing height with a stadiometer and record to the nearest 0.1cm. No shoes, arms relaxed, faces positioned with outer canthus and upper ear aligned horizontally.

Take two measurements approximately one year apart, most accurate between 11-13 months.

Height velocity = difference in height divided by difference in age

Midage is the midpoint between two measurement dates

Height velocity is the most sensitivie measure for growth abnormalities during all types of chronic illness

During puberty, peak height velocity is 6-12 cm/year in males, and 5-10 cm/year in females. The age of peak height velocity varies significantly

Any child over 2 years old with less than 4 cm/year height velocity is a sign of needing more close monitoring and possibly investigation (95% of children grow faster than this)

This calculator uses the Kelly data from 2014 for average maturing children, which from a diverse, healthy, and large cohort of 5-19 year olds. The measurement intervals were 11-13 months.[1]

The midpoint age data has intervals of 0.25 years. If the midpoint age is not within 0.05 of a reference data point then the calculator uses cubic interpolation

Unlike weight and height centile curves, a child is not likely to "track" along a given percentile for HV

Age

Age at First Date

Age at Second Date

Age Difference

Midpoint Age

Annualised Height Velocity

Midpoint Age Z-Score

Midpoint Age Centile

Calculator coded by Jeremy Steinberg, contact for suggestions