How Tall Am I Going to Be?
Two things predict your adult height reasonably well: how tall your parents are, and how tall you are now for your age. This page explains the formula, how to sharpen it, what moves the answer, and why any prediction should come as a range.
The quick way: your genetic target
Your parents are the strongest single clue. Average their heights, then adjust for sex:
| You are | Estimated adult height |
|---|---|
| Male | (father + mother) ÷ 2 + 6.5 cm (+2.5 in) |
| Female | (father + mother) ÷ 2 − 6.5 cm (−2.5 in) |
Example: a father of 180 cm and a mother of 165 cm average 172.5 cm. A son is expected near 179 cm, a daughter near 166 cm. The honest answer is a range, roughly ±5 cm around that number, and the individual result can sit outside it.
Sharpening it with your height now
If you are still growing, your own measurements add information the parent formula cannot. The calculator above compares your current height and age with the CDC growth charts, projects how much growing is left, and blends that with the parental estimate. It widens the range when the two methods disagree and when you are younger, because a long stretch of growth remains uncertain.
Timing matters as much as height. Two 13-year-olds at 150 cm can end up 10 cm apart if one has already had their growth spurt and the other has not started. Say honestly where you are in puberty when you use the tool.
What changes the answer
- How tall your parents are. The bulk of the difference between people is genetic, which is why the parents' average is the starting point.
- When puberty starts. Girls usually start between 8 and 13, boys between 9 and 14. Late starters grow for longer.
- Sleep, nutrition and health. These do not lift your ceiling, but years of poor sleep, too little food or an untreated condition can stop you reaching it.
- Which side of the family. Grandparents and aunts and uncles can pull a result away from the parental average.
What does not work
- Supplements and stretching devices. Nothing you can buy lengthens bone. Hanging and stretching can make you measure about a centimetre taller for a few hours, then it reverses.
- Shoe size. Feet finish growing before legs and spine, so big feet at 13 say little about the final number.
- Any prediction to the centimetre. Be wary of a tool that gives one exact figure with no range.
For more on timing, see how much more you will grow and when growth stops.
↑ Run the free predictor — 60 seconds, result shown without an account.
Frequently asked questions
How can I find out how tall I am going to be?
Average your parents' heights, then add 6.5 cm (2.5 in) if you are male or subtract 6.5 cm if you are female. That mid-parental figure is your genetic target. If you are still growing, compare your current height with growth-chart averages for your age to adjust it. Published target-height methods land within 8.5 cm (3.3 in) for about 95% of people (Tanner et al., 1970), so treat the answer as a range.
How tall will I be if my parents are short?
Usually shorter than average, but the formula only gives a target, not a guarantee. Children of short parents commonly sit on a low percentile line and follow it. Height also varies between siblings of the same parents, which is why the estimate comes as a range of roughly 5 cm either side.
Can I predict my adult height from my height now?
Yes, once you are past early childhood. Compare your height and age with the CDC growth charts to see your percentile, then project forward. Accuracy depends on when puberty starts: an early developer looks tall now and finishes closer to average, while a late developer looks short now and catches up.
Is the 'double your height at age 2' rule accurate?
It is a rough rule, not a reliable one. It works reasonably for boys, tends to overestimate for girls, and ignores your parents' heights. The mid-parental method is better for anyone past toddlerhood.
When will I stop growing?
Most girls reach adult height around 14–16 and most boys around 16–18, though growth can continue a little later. Growing under 1 cm over twelve months, with puberty finished, usually means growth is nearly over. Only a hand and wrist X-ray shows for certain whether growth plates are still open.
This tool provides a statistical estimate for general information only. It is not medical advice, diagnosis or treatment. If you are concerned about your growth or your child's, speak to a paediatrician or family doctor.