GetTall

Free measurement trend calculator

Turn two measurements into a rate.

See the measured change, annualized rate and comparison with the selected CDC median curve across the same age interval.

Measurement-to-measurement change

Calculate growth velocity.

Add age and a CDC chart reference to compare two measurements taken at least 90 days apart.

Height unit
Height unit
01 Reference at later measurement
CDC chart reference
02 Earlier measurement
Standing height
03 Later measurement
Standing height

Use the same setup, time of day and technique for both measurements.

Your measurement trend will appear here.

Longer, consistently measured intervals are less sensitive to everyday measurement noise.

Before calculating

The measurement method is part of the data.

  1. 01
    Keep the setup consistent

    Use the same flat floor, vertical surface and measuring technique for both dates.

  2. 02
    Use enough time

    Short intervals magnify ordinary posture and measurement variation. This tool requires at least 90 days.

  3. 03
    Look for a pattern

    Two points create a rate; more well-measured points provide better context.

Transparent formula

Change ÷ days × 365.25.

The calculator subtracts the earlier height from the later height, divides by the number of days between measurements and annualizes the result.

For the basic interpretation, it maps both measurements to the selected CDC stature reference. It compares the observed rate with the change in the CDC median curve across the same ages and shows the percentile movement. Individual puberty timing can produce a different pace from that median curve.

Concerned about growth or an unexpected change? Recheck the measurement and speak with a pediatrician or qualified clinician.

See the formula and worked example →

View the CDC data source ↗