Ideal Weight Calculator

By Sofia Andersen · Last updated 15 October 2026

There is no single weight that is right for everyone at your height. What this calculator gives you is a range: the band of weights that puts your BMI between 18.5 and 24.9, plus the older Devine figure for comparison. A range is more honest, because build, muscle, and age all shift where any one person sits comfortably.

General information only. This is not medical advice, a diagnosis, or treatment. If you have questions about your weight or health, talk with a qualified health professional. Urgent symptoms need urgent care, not a calculator.

Forget one magic number

Enter your height and sex. You get two things back. The first is the healthy weight range for your height, from the BMI band. The second is the Devine number, a single figure from a formula first used for medicine dosing. Keep both in view. The range is the useful one for most people. The Devine figure is a historical reference point, and it tends to sit somewhere inside the range. The calculator opens in metric mode with an imperial switch. You can also flip between the healthy-range view and the Devine view. Weights round to one decimal place, so 58.62 kg shows as 58.6 kg.

A formula from 1974

The Devine formula starts at 5 feet and adds the same amount for every inch above it:

Men: 50 kg + 2.3 kg for each inch over 5 feet

Women: 45.5 kg + 2.3 kg for each inch over 5 feet

Under 5 feet, subtract 2.3 kg for each inch below. The formula was designed in the 1970s to estimate body weight for drug dosing, not to set a beauty standard. That matters, because it was never meant to say what anyone ought to weigh.

The range beside it comes from the healthy BMI band applied to your height:

Lower end = 18.5 × height (m)²

Upper end = 24.9 × height (m)²

Both numbers, side by side

Take a man who is 5 feet 10 inches tall. That is 70 inches, or about 1.78 m. Devine: 70 − 60 = 10 inches over 5 feet. Then 2.3 × 10 = 23. Add the base: 50 + 23 = 73 kg. Healthy range: square the height in metres, 1.78 × 1.78 = 3.1684. Then 18.5 × 3.1684 = 58.6 kg, and 24.9 × 3.1684 = 78.9 kg. So the range is 58.6 to 78.9 kg, and the Devine figure of 73 kg sits inside it, toward the upper half.

For a woman who is 5 feet 4 inches (64 inches): 64 − 60 = 4, 2.3 × 4 = 9.2, and 45.5 + 9.2 = 54.7 kg. Again, that single figure is best read next to the range for her height, not on its own.

Who the range fits badly

A single ideal weight cannot see your frame. Someone broad-shouldered with a lot of muscle can sit near the top of the range and be perfectly healthy. Someone slight and lightly built may feel best near the bottom. Age plays a part too: many people carry a little more weight in midlife without any harm, and a little extra can even protect older adults who get ill.

So use the range as a rough map, not a target painted on the wall. If your weight sits a bit outside it and you feel well, eat well, move regularly, and your check-ups look fine, that is a conversation for your next appointment, not a reason to panic. If it sits well outside, the same conversation is still the right next step, because weight is only one part of health.

For the fuller picture, the BMI calculator shows where you sit in the band, the body fat percentage calculator adds the muscle-versus-fat angle, and the calorie calculator estimates what keeps weight steady. The BMR calculator works out what your body uses at rest. There is also a longer read, What is a good BMI?, on healthy ranges, limits, and BMI versus body fat. Or browse all health calculators and all calculators on CalcKits.

Frequently asked questions

What is my ideal weight?

There is no one ideal weight for a given height. A healthy range, the weights that put BMI between 18.5 and 24.9, is a better guide, and where you sit in it depends on build, muscle, age, and health history.

Is the Devine formula accurate?

It is a simple rule from the 1970s, made for drug dosing. It gives a reasonable ballpark for many adults, but it ignores frame, muscle, and age, so treat it as a reference point next to the range, not a verdict.

How is ideal weight different from a BMI range?

An ideal weight is one number. A BMI range is a band of weights for your height, from 18.5 to 24.9. The band is more forgiving and more honest, because healthy bodies come in different shapes.

What if I am muscular?

Muscle is heavy. A muscular person can sit above the range while carrying little body fat. In that case, waist size and body fat percentage tell you more than the scale alone.

Does age change my ideal weight?

It can shift where you sit comfortably. Many people carry a little more weight in midlife without any harm, and a little extra can even protect older adults who get ill. The range stays the same, but how you read it changes with age.

Nothing here is medical advice, a diagnosis, or treatment. It is general information, and it cannot replace a qualified health professional who knows your history. If symptoms worry you, or anything feels urgent, get urgent care rather than waiting on a calculator result.

Sources

• Devine formula: drug dosing weight estimation (1974)
• Centers for Disease Control and Prevention: About Adult BMI and healthy weight guidance