1
Print at 100%
In the print dialog choose 'Actual size' or 100%, not 'Fit to page'. Fitting shrinks the scale and every measurement comes out wrong.
Five A4 pages you print, cut and tape together into a 170 cm giraffe with a true-to-size scale from 70 to 170 cm. Beside the centimetres, the median height of boys and of girls at every age on the WHO standards, and a QR code that opens the app so the measurement is logged on the spot. Free, no sign-up.
PDF, five A4 pages, in colour · Hebrew version

1
In the print dialog choose 'Actual size' or 100%, not 'Fit to page'. Fitting shrinks the scale and every measurement comes out wrong.
2
The foot of the first page carries a 10 cm calibration bar. Hold a ruler against it: if it is not exactly 10 cm, print again with the right setting.
3
Cut along the dashed line at the foot of each page (except the first) and lay it so its bottom line sits exactly on the same number on the page below.
4
The 70 line on the first page must sit exactly 70 cm off the floor. Measure with a tape before you stick it to the wall.
5
Back to the wall, heels together, eyes level. Rest a book on the head, flat, and mark the line. Write the date next to every mark.
Enter the wall measurement in KidGrowth and see it on the WHO growth curve, next to sizes, vaccinations and a reminder to measure again.
Get KidGrowth on Google PlayBecause babies are measured lying down, and a wall chart suits a child who stands steadily, usually from around a year, when the median height is about 75 cm. It runs to 170, enough for most children into their teens.
They are the median height (50th percentile) on the World Health Organization standards, the same data behind the app and the calculator. Half of children of that age are taller than the line and half are shorter. It is context, not a grade; a child above or below the line is growing at their own pace.
The chart is calibrated for A4 at 100%. On US Letter paper also print at 100%, never 'Fit to page'; the cutting margins differ slightly but the scale holds. The 10 cm bar is the check either way.
Photograph the wall every few months, or type the measurement into the app, which places it on the WHO curve and shows the percentile and the trend. The wall is the moment; the app is the line.