Ideal Body Weight Calculator
1Your measurements
Your body mass index
–
25Obesity I
30Obesity II
35Obesity III
40+
Your BMI, three ways
Your WHO category always comes from the standard BMI: weight in kilograms divided by height in meters squared. There is only one WHO formula. The new BMI and the ponderal index are research alternatives that correct for very short or very tall people; they have no official categories. The eight formulas further down estimate a target weight, they do not change your category.
Ideal body weight by formula
The main result above is your BMI, classified with the World Health Organization (WHO) adult categories. The WHO range is the only one here it endorses; the eight formulas below are single targets from clinical practice, shown on the same color scale.
Bar color = BMI category of the result, same colors as the scale aboveYour current weight
Next step: turn a target weight into daily calories with our TDEE calculator, then plan the walking or incline work that gets you there.
Open the TDEE calculatorFor general information only, not medical advice. These formulas estimate population averages and can be off for an individual; talk to your doctor or a registered dietitian before changing your diet or training, especially with a health condition, during pregnancy or for anyone under 18.
Free tool · Updated November 1, 2026
What should you weigh for your height?
Ideal body weight has no single answer. The calculator runs the eight formulas doctors and dietitians use most, places you on the BMI scale and checks your frame size from your wrist, so you can see where the estimates agree.
Short answer
Your ideal body weight depends on the formula: for a 5 ft 9 in man the common formulas range from about 152 to 166 lb, and the healthy BMI range runs from about 126 to 168 lb. Enter your height, sex, age and wrist size below to see all eight results, your BMI and your frame size in pounds and kilograms.
Key takeaways
- No formula gives one true ideal weight; a range is more useful than a single number.
- BMI between 18.5 and 24.9 is the healthy range used by the WHO and the CDC for adults.
- Wrist size adjusts for bone structure: a large frame carries more weight at the same height.
- BMI and these formulas ignore muscle, so athletes often read as overweight.
Ideal body weight formulas were written for different jobs. Devine and its revisions came from drug dosing, Hamwi from diet planning, Lorentz, Broca and Creff from European clinical practice. They agree within a few pounds for average heights and drift apart for very short or very tall people.
That is why the calculator shows all of them next to your BMI and the healthy BMI range for your height. Where the estimates cluster is a reasonable target; the spread shows how uncertain any single number is.
The Ideal Body Weight Formulas Explained
Most formulas start from a base weight at 5 feet and add a fixed amount for each inch above it. Devine (1974) is the most widely used in U.S. hospitals. Robinson and Miller (both 1983) refitted it to later population data, and Hamwi (1964) is the quick rule many dietitians learned.
The European formulas work in centimeters. Broca (1871) subtracts 100 from your height. Lorentz trims that for taller people and more for women. Creff adds age and a body-build factor, and Monnerot-Dumaine uses wrist circumference as a measure of bone structure.
| Formula | Men | Women | Example: 5 ft 9 in manExample |
|---|---|---|---|
| Devine (1974) | 50 + 2.3x kg | 45.5 + 2.3x kg | 156 lb (70.7 kg) |
| Robinson (1983) | 52 + 1.9x kg | 49 + 1.7x kg | 152 lb (69.1 kg) |
| Miller (1983) | 56.2 + 1.41x kg | 53.1 + 1.36x kg | 152 lb (68.9 kg) |
| Hamwi (1964) | 48 + 2.7x kg | 45.5 + 2.2x kg | 159 lb (72.3 kg) |
| Lorentz (1929) | H – 100 – (H – 150) / 4 | H – 100 – (H – 150) / 2.5 | 152 lb (68.9 kg) |
| Broca (1871) | H – 100 | H – 100 | 166 lb (75.3 kg) |
| Creff | (H – 100 + age / 10) x 0.9 | same, x 0.9 slender or x 1.1 broad | 156 lb (70.9 kg), age 35 |
| Monnerot-Dumaine | (H – 100 + 4 x wrist) / 2 | same | 161 lb (73.2 kg), 7 in wrist |
BMI Categories and What They Miss
Body mass index is weight in kilograms divided by height in meters squared (or 703 times pounds divided by inches squared). The World Health Organization and the National Heart, Lung, and Blood Institute use the same adult cut-offs.
BMI cannot tell muscle from fat, so muscular people often read as overweight. It also says nothing about where fat sits; waist size adds that. For a closer look at body composition, use our navy body fat calculator.
| BMI | Category | At 5 ft 9 in |
|---|---|---|
| Below 18.5 | Underweight | under 126 lb |
| 18.5 to 24.9 | Healthy weight | 126 to 168 lb |
| 25 to 29.9 | Overweight | 170 to 202 lb |
| 30 to 34.9 | Obesity, class 1 | 204 to 236 lb |
| 35 to 39.9 | Obesity, class 2 | 238 to 270 lb |
| 40 and above | Obesity, class 3 | 271 lb and above |
Frame Size From Your Wrist
Measure around the wrist just above the wrist bone, on your dominant side. Divide your height by that circumference (same units): the higher the ratio, the smaller the frame. A small frame usually sits at the lower end of the formula results, a large frame at the upper end.
| Ratio (height / wrist) | Men | Women |
|---|---|---|
| Small frame | above 10.4 | above 11.0 |
| Medium frame | 9.6 to 10.4 | 10.1 to 11.0 |
| Large frame | below 9.6 | below 10.1 |
From a Target Weight to a Plan
- Find your calories. The TDEE calculator turns your weight, height, age and activity into daily calorie targets for slow, steady loss.
- Add daily walking. Brisk walking on an incline burns more calories than walking on flat ground; the treadmill calorie calculator shows how much for your speed and incline.
- Train at home. A treadmill removes weather and commute from the plan; see our best treadmills for weight loss or let the treadmill finder match one to you.
- Follow a simple routine. Our guide on how to lose weight on a treadmill covers workouts and pacing.
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- TitleIdeal Body Weight Calculator
- PublisherFitGearHQ
- URLhttps://fitgearhq.com/ideal-body-weight-calculator/
- Updated
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Checklist Before You Set a Target Weight
4 checks
Tap a number to check off that step.
- 01
Measure height without shoesStand against a wall, heels together, and mark the top of your head.
- 02
Weigh in the morningSame scale, after the bathroom and before breakfast, for a steady reading.
- 03
Measure your wristJust above the wrist bone, on your dominant side, with a soft tape.
- 04
Read the range, not one numberWhere the formulas cluster is a better target than any single result.
Common Mistakes to Avoid
Mistake 1Treating one formula as exact
Instead: The formulas differ by 10 lb or more at the same height.
Mistake 2Ignoring muscle
Instead: Muscular people often read as overweight on BMI; check body fat as well.
Mistake 3Using these formulas for children
Instead: Children and teens need age and sex growth charts instead.
Mistake 4Aiming too low too fast
Instead: A loss of 5 to 10% of your weight already brings health benefits.
The Bottom Line
- Eight formulas: Devine, Robinson, Miller, Hamwi, Lorentz, Broca, Creff and Monnerot-Dumaine.
- BMI with the six adult categories, and the healthy range for your height.
- Frame size from height and wrist circumference.
- US and metric units; the link keeps your inputs.
Frequently Asked Questions
The standard BMI: weight in kilograms divided by height in meters squared (or 703 x pounds / inches squared). It is the only formula the WHO categories are based on. The new BMI and the ponderal index are alternatives for research and for very tall or short people.
None is accurate for everyone. Devine is the most widely used in U.S. medicine; comparing several and reading the range is more reliable.
For adults, a BMI from 18.5 to 24.9. The calculator converts that range into pounds and kilograms for your height.
Yes. People with a large frame usually carry more bone and muscle, so their target sits at the upper end of the range.
At the same height, men carry more lean mass on average, so most formulas start from a higher base weight for men.
Not very. BMI cannot tell muscle from fat, so a body fat estimate is more useful for muscular people.
No. These formulas are for adults; children and teens need growth charts from a pediatrician.
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