change / Height
Height growth calculator
Two heights, and the growth between them.
Answers now
Growth
+2.5cm
2026-03-01 — 2026-09-01
- 123.5 cm
- Earlier
- 126.0 cm
- Later
- 184 days
- Over
Later minus earlier; dates subtracted on the calendar. No health threshold is involved.
Step by step
Both numbers go to centimetres first (1 inch = 2.54 cm), then subtract. Days are counted on the calendar rather than estimated as “about six months” — 1 March to 1 September is 184 days, not 180.
What this number cannot tell you
This is a difference between two numbers, not a growth-velocity percentile. It cannot tell you whether the growth was enough — that needs a velocity reference by age, and no such table is published here yet. If one measurement was lying and the other standing, part of the difference is the method rather than the child, and nothing here subtracts it for you.
An example
123.5 cm on 1 March, 126.0 cm on 1 September: 2.5 cm over 184 days.
Common questions
- Will this tell me whether my child is normal?
- No. What happens here is arithmetic, and “normal” needs an age-based reference table before it means anything — there is none behind these figures. The section above spells out what stays out of reach.
- Do the numbers I type reach your server?
- No. Everything is worked out in the browser on this device, and the page has no channel for sending data out — the site’s security policy closes that route outright, so it is not a promise you have to take on trust. Reload and the numbers are gone; to keep them, copy them.
Next
The others in the same group.
Child height percentile calculator
One height measurement, placed among children of the same age and sex.
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The height records you already have, plotted at their real spacing in time.
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A percentile at a given age, in centimetres.
Compared with peersOpen