Measure better
How to measure height accurately at home
A growth trend is only as good as its measurements. Five steps, one flat surface, and a little consistency — that's the whole secret.
Stand barefoot against a flat wall with heels and shoulder blades touching, gaze level, and press a flat headpiece (a hardcover book works) at a right angle. Measure in the morning if possible and repeat every 60–90 days — height varies 1–1.5 cm during the day.
The 5-step standing protocol (ages 2+)
- Remove footwear. Shoes off, thick socks off, bulky hairstyles loosened.
- Stand against a flat wall. Heels, hips and shoulder blades touching the wall, on a hard floor.
- Level the gaze. Look straight ahead — the line from ear canal to eye socket roughly parallel to the floor (the Frankfort plane).
- Use a flat headpiece. A hardcover book or rigid square pressed at a right angle against the wall, lowered to the crown of the head. Mark or read at that point.
- Record consistently. Same wall, same time of day, same protocol — every time. GrowTall tags each record so the history stays comparable.
Infant length (under age 2)
Babies are measured lying down, and it takes two people:
- Use a firm, flat surface or a length board.
- Head against the fixed headboard, body straight and centered.
- Gently extend the legs — no forcing.
- Measure crown to heel with the mobile headpiece.
Length reads slightly longer than standing height, which is exactly why the WHO reference switches at age 2. GrowTall switches protocols automatically based on age.
Why time of day changes your height
Spinal discs compress as you stand and move, then rehydrate overnight. The result: most people are about 1–1.5 cm taller in the morning than in the evening. Mixing morning and evening readings makes a flat trend look wobbly.
Best practice: measure in the first hour after waking when possible, or at least always at the same time of day — and tag morning vs. evening in GrowTall so the trend stays clean.
Common mistakes that ruin a trend
- Measuring on carpet (the floor compresses).
- Keeping shoes or thick socks on "just this once".
- Reading the book's edge at an angle instead of a true right angle.
- Comparing a morning measurement to last month's evening measurement.
- Measuring daily and expecting to see growth — real skeletal change needs 60–90 days.
Avoid those and your height tracker becomes genuinely informative. The WHO and CDC references do the rest.
Common questions
How often should I measure?
Every 60–90 days for children. Natural growth is only a few centimeters per year, so closer together mostly measures daily fluctuation rather than growth.
Morning or evening?
Morning is ideal — you are at your tallest and the value is more repeatable. Whenever you choose, stay consistent and tag the time of day in GrowTall.
Is a wall tape measure accurate enough?
Yes, if the floor is hard, the wall flat, the tape straight, and you use a flat headpiece at a true right angle. Protocol consistency matters more than owning a stadiometer.
See the bigger picture of growth.
Track every measurement, understand the trend and keep a reliable growth record — free to start, no ads.