Height predictor: how tall will your child grow?

Get the estimate

Enter the father's height, the mother's height, and whether the child is a boy or a girl. Switch between centimetres and feet and inches with the buttons above the fields; the answer comes back in both.

How to read the answer

The tool gives you a range, not a number, and the range is about seventeen centimetres wide. That width isn't a flaw; it's the honest answer. From this much information, nothing more precise can be said.

A range like 5'4" to 5'10" disappoints, because everyone wants one number. But any tool that gives one number is painting it over exactly the same uncertainty.

So treat this as entertainment. The real instrument for judging a child's growth is the growth chart your doctor fills in at every visit, not any formula.

What the mid-parental method actually does

The arithmetic is simple: average the parents' heights; add 6.5 cm for a boy, subtract 6.5 for a girl; allow 8.5 cm either side of the result. What comes out is what paediatricians call the 'target height'.

The method is genuinely used in paediatrics, but never alone. Doctors read it against the child's growth chart, to check the child is growing within the range its family predicts.

Where it comes from is worth saying. The method is Tanner, Goldstein and Whitehouse, published in 1970 and built on British children. Because it is stated relative to the parents' own heights rather than against a population average, it travels better than a growth chart would; a short couple's target height is short wherever they live.

Its real weakness in India is generational. The formula assumes a child grows up in roughly the conditions the parents did. Where a generation has eaten better than the one before it, children commonly overshoot the estimate, and average adult height in India has been rising for decades. Read the range as your family's starting point, not as a ceiling.

Genes give a range, not a number

Hundreds of genes affect height, and they arrive from the parents in fresh combinations, which is why siblings in one house end up different heights.

The rest is environment: nutrition, especially in the first two years, repeated illness, sleep, and the timing of puberty. Some of those are in your hands.

One generation-sized example: the average height of young Indians has risen over the past fifty years. Same genes; better food and health. Genes set the range. Where in the range a child lands is substantially everything else.

What actually moves the range, by age

The environment half of height is not one thing applied evenly across childhood. Different years reward different attention, and the early ones count for the most.

Birth to two is the window that matters most, and the one that cannot be revisited. Exclusive breastfeeding for the first six months, then adequate complementary feeding; keeping infections short and few, because every bout of diarrhoea or pneumonia costs growing time; and the vitamin D supplementation most Indian paediatricians advise, since deficiency here is close to universal.

Two to five is where the diet has to broaden rather than simply grow. Protein at every meal, dal, curd, paneer, egg, fish or meat, plus iron and zinc, because anaemia is common in Indian children and slows growth as well as learning.

Five to ten is steady growth, and protein and calcium continue to do the work: dairy, ragi, til and greens. This is also the age at which a year's growth is easiest to measure at home. A pencil mark on the door frame, once a year, on the same date.

Ten and over belongs to the puberty growth spurt, and by then food is only part of it. Sleep is when growth hormone is released, so late bedtimes are a growth issue and not only a school one; physical activity, particularly running and jumping, helps; and chronic stress and chronic untreated illness both cost centimetres.

What to eat is a longer subject than this page, and one that changes with what a family eats and can buy. Our guide to increasing height in children covers the food side properly, including what is worth spending money on and what is not.

Tall parents, short child — why it happens

'My husband is six feet, I'm five-seven — why is our son the shortest in class?' The answer is usually about timing, not height.

Some children are late bloomers. This is 'constitutional delay', and it runs in families. They trail the line-up for years, then keep growing at sixteen and seventeen after everyone else has stopped.

The useful question is whether the father was a late bloomer himself. Ask the grandparents; the answer usually lives in the family.

What puberty timing does to height

The last big growth spurt comes with puberty. Girls hit it around ten to twelve; boys about two years later, at twelve to fourteen.

That's why girls tower over boys in class seven and eight. It's temporary: boys start later, grow longer, and finish taller on average.

There is a paradox worth knowing. The child who hits puberty earliest looks tallest in class but stops growing soonest, and can finish shorter than expected. Signs of puberty before eight in a girl or nine in a boy are worth showing to a doctor.

Stunting: when short is a health problem rather than a family trait

Most short children are simply short, and it is worth being clear about that before this section is read as a warning. But India has a real and measurable problem underneath the ordinary variation, and a page about height that does not mention it is not being straight with you.

Stunting has a specific definition. A child is stunted when their height for their age falls more than two standard deviations below the WHO standard, which is roughly below the 2nd percentile. It is a marker of chronic undernutrition and repeated infection over months and years, not of a few bad weeks.

The most recent National Family Health Survey, covering 2019 to 2021, found 35.5% of Indian children under five were stunted. It had fallen from 38.4% five years earlier. It is markedly higher in rural areas, 37.3%, than in urban ones, 30.1%, and tracks household income closely.

What matters for a parent is that stunting is largely preventable and its window is early. The same first-two-years measures do the work: adequate feeding, prompt treatment of infections, and keeping the routine immunisations on schedule. It is also partly reversible in early childhood, and much less so after.

The thing to act on is not a single measurement but a trend. A child who is short and growing steadily along their own line is usually fine. A child who is short and falling away from their line needs a doctor.

This is not a screening tool

Sometimes short stature signals a thyroid problem, malabsorption, chronic illness or hormone deficiency. This tool cannot detect any of those, and doesn't claim to.

It also cannot tell you what your child's height should be at seven, or at eleven. That question has an answer, but not from this arithmetic: adult target height does not convert into an expected height at a given age. What answers it is a growth chart, which compares your child against thousands of children of exactly their age and sex. Our growth calculator does that, for height from birth to nineteen.

One question that comes up about those charts, and deserves a straight answer: should Indian children be measured against an Indian reference rather than an international one? For the under-fives, no. The WHO standard was built from children in six countries, India among them, all raised in conditions favourable to growth, and it found that well-fed, healthy under-fives grow much alike whatever their ethnicity. A reference built from how Indian children actually grow would fold the country's undernutrition into the definition of normal. Above five, where genuine population differences do open up, the Indian Academy of Pediatrics published Indian charts in 2015, and those are what Indian paediatricians use.

The signs that matter are different from a single number: a child crossing lines downward on the growth chart, growing less than four centimetres a year in mid-childhood, or falling behind in both height and weight together.

The easiest home habit is a pencil mark on the door frame once a year. How much a child grew in a year says more than how tall they are today.

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