Ideal weight calculator
Enter your height in feet and inches or in centimeters to see your ideal weight from four well-known formulas, along with the healthy weight range for your height. There is no single agreed answer, and seeing how much the formulas disagree is useful in itself.
Uses a standard published formula, explained below. The result is an estimate, not medical advice, and its limits are explained further down the page.
Your details
Wrap your thumb and middle finger around your other wrist. If they overlap, choose small; if they just touch, medium; if they do not meet, large.
Average across four formulas
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Range across formulas
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Healthy BMI weight range
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In the other unit
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| Formula | Kilograms | Pounds |
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Show the working
—These formulas were not designed to tell you what to weigh. Most were developed for clinical drug dosing, not health guidance, and none accounts for muscle mass, bone density, age or ancestry. Body composition matters more than the number on a scale. If weight is a concern, discuss it with a doctor or registered dietitian rather than working toward a formula's output.
Where these formulas came from
Most ideal weight calculators leave this out, but it changes how seriously the results should be taken.
The Devine formula, published in 1974, was designed to work out medicine doses, not healthy body weights. It was never tested as a health target. It became the standard ideal weight formula almost by accident, because it was simple and already widely used.
The Hamwi formula dates from 1964 and was intended for planning the diets of people with diabetes. The Robinson and Miller formulas, both from 1983, were attempts to correct Devine using real population data.
All four work the same way: a starting weight for someone five feet tall, plus a fixed amount for each extra inch of height. Because of this, they work poorly for very short or very tall people, and none of them was based on actual health outcomes.
Why the four formulas disagree
Enter your height and compare the four results. For most heights, they differ by several kilograms, and there is no strong reason to prefer one over the others.
That spread is the honest answer. There is no single ideal weight for a given height, and the fact that four serious attempts give four different numbers shows how uncertain the idea is. It is not a reason to take the average.
The healthy BMI range shown alongside is usually wider than all four formulas, and it comes from large studies of health and life expectancy rather than from medicine dosing. That makes it the more reliable guide, although it shares all the limits of BMI itself.
What the formulas cannot take into account
The biggest gap is muscle. A person who trains regularly can weigh more than every formula suggests and still have low body fat. Because muscle is denser than fat, building muscle while losing fat can leave your weight the same or even higher while your health improves.
Body frame is included only as a rough 10% adjustment up or down, which is better than ignoring it but far from precise. Bone density, body proportions, age and ethnic background are not included at all, even though healthy body composition does differ between populations. For South Asian adults, health guidelines often use a lower BMI range, which you can see in the BMI calculator.
Better questions to ask than your ideal weight
Instead of aiming for one number, look at measures that are more closely linked to health. These include your waist-to-height ratio (a waist under half your height is generally a good sign), your blood pressure, your resting heart rate and how well you feel and function day to day.
A weight at which you sleep well, move comfortably and have healthy blood test results without constant effort is a better ideal weight than anything a 1974 dosing formula can give you.
Frequently asked questions
What is the ideal weight for my height?
It depends on the formula, which is why this calculator shows four of them plus the healthy BMI range. For example, for a man who is 5 feet 8 inches tall, the four formulas give roughly 67 to 70 kg, while the healthy BMI range is wider. Treat any single number as a rough guide, not a target.
Is ideal weight the same as a healthy weight?
No. Ideal weight formulas give one number based on height and sex, while a healthy weight is a range that depends on your body composition, fitness and medical history. The healthy BMI range is usually wider than any of the formulas.
Why do the four formulas give different answers?
They were developed separately, for different purposes and using different groups of people. Devine and Hamwi were designed for medical dosing and diet planning, not as health targets, so their disagreement reflects real uncertainty.
Which formula should I use?
None of them as a strict target. If you want one reference, use the healthy BMI range shown alongside, because it is based on large studies of health outcomes rather than medicine dosing.
How do I find my body frame size?
Wrap your thumb and middle finger around your other wrist. If they overlap, you probably have a small frame. If they just touch, a medium frame, and if they do not meet, a large frame. This is only a rough guide.
Do these formulas work for athletes?
Not well. They will give a weight that is too low for anyone with a lot of muscle, because they cannot tell muscle from fat. A body fat measurement is far more useful.
Does ideal weight change with age?
The formulas do not change with age, which is one of their weaknesses. In reality, body composition changes as people lose muscle with age, and some evidence suggests a slightly higher BMI is not harmful in older adults.