Ideal weight calculator
Your ideal weight by four formulas, side by side.
- Devine (1974)
- 73.2 kg
- Robinson (1983)
- 71.1 kg
- Miller (1983)
- 70.4 kg
- Hamwi (1964)
- 75.2 kg
- BMI 18.5–24.9 (WHO)
- 58.6–78.9 kg
- BMI 18.5–22.9 (Asian Indian)
- 58.6–72.6 kg
For adults 5 ft (152.4 cm) and taller. Most of these formulas were built for drug dosing, not as personal health targets. Not medical advice: in pregnancy, with an eating disorder or a condition that affects your weight, ask your doctor before setting a goal.
This ideal weight calculator shows what the Devine, Robinson, Miller and Hamwi formulas give for your height and sex, next to the weights that put you in the normal BMI range. Most of these formulas were built to dose medicines, not to set health goals, so the page explains where each number comes from.
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What is an ideal weight?
In these formulas, ideal body weight is a figure doctors and pharmacists use to dose some medicines, worked out from height and sex. This ideal weight calculator shows the four common formulas and the weights for a normal BMI at your height. None of them is a personal target; a healthy weight is a range.
- Devine (1974), Robinson (1983), Miller (1983) and Hamwi (1964)
- Weights for BMI 18.5–24.9 (WHO) and 18.5–22.9 (Asian Indian) at your height
- Kilograms or pounds
- Formulas from 5 ft (152.4 cm); the BMI ranges for any adult height
How it works
How does this ideal weight calculator work?
It converts your height to inches over 5 feet, then applies each formula: a base weight at 5 feet plus a fixed amount for every inch above it, different for men and women. It shows all four side by side, and the weights that give a normal BMI at your height on two scales.
Measure your height over 5 feet
All four formulas start at 5 ft, or 152.4 cm. The calculator converts centimetres to inches, 2.54 cm each, and subtracts 60. At 5 ft 10 in you are 10 inches over; at 175 cm, about 8.9 inches over.
- Below 5 ft the formulas are not defined, so only the BMI ranges show
- Sex changes the base weight and, in three of the formulas, the amount per inch
Apply the four formulas
Each formula adds kilograms per inch to a base weight. Devine’s, from 1974, came into use for dosing drugs. Robinson fitted the same idea to Metropolitan Life Insurance height and weight tables in 1983, and Miller refitted it to the later tables. Hamwi’s, from 1964, has no published method.
- Robinson’s regression gave 51.65 kg plus 1.85 kg an inch for men, usually rounded to 52 and 1.9
- Hamwi’s rule was in pounds: 106 lb plus 6 lb an inch for men, 100 lb plus 5 lb for women
Compare with the normal BMI range
The calculator also turns BMI 18.5 to 24.9, WHO’s normal range, and 18.5 to 22.9, the Indian guidance for Asian Indian adults, into weights for your height. These are ranges, so they show how much room a healthy weight has.
- At 5 ft 10 in: 58.5 to 78.7 kg on the WHO range
- In the middle of the height range the formulas sit inside it; at the ends they drift (Peterson 2016)
Read the spread
The main figure runs from the lowest to the highest of the four. The spread shows how much the formulas disagree: at 5 ft 10 in, 70.3 to 75.0 kg for a man. It grows towards the short and tall ends, because the amounts per inch differ.
- For tall men Hamwi gives the most and Miller the least
- For short people the order flips, and Miller gives the most
Formulas
Which formulas does the calculator use?
Each is a base weight at 5 feet plus a set amount for every inch above it. In kilograms: Devine gives 50 plus 2.3 per inch for men and 45.5 plus 2.3 for women; Robinson 52 plus 1.9 and 49 plus 1.7; Miller 56.2 plus 1.41 and 53.1 plus 1.36; Hamwi 48 plus 2.7 and 45.5 plus 2.2.
Men: 50 + 2.3 × I · Women: 45.5 + 2.3 × IMen: 52 + 1.9 × I · Women: 49 + 1.7 × IMen: 56.2 + 1.41 × I · Women: 53.1 + 1.36 × IMen: 48 + 2.7 × I · Women: 45.5 + 2.2 × IW = BMI × H²- Each formula gives ideal body weight in kg
- I: inches of height over 5 ft, which is height in cm ÷ 2.54 − 60
- W: weight in kg; H: height in metres
Compared
How do the formulas compare across heights?
They agree best in the middle of the height range and drift apart towards the ends. For men, Hamwi adds 2.7 kg an inch and Miller 1.41 kg, so at 6 ft 4 in they are more than 12 kg apart. For a woman of 5 ft, Miller gives 7.6 kg more than Devine or Hamwi.
| Height | Devine | Robinson | Miller | Hamwi | BMI 18.5–24.9 |
|---|---|---|---|---|---|
| Man, 5 ft 4 in (162.6 cm) | 59.2 | 59.6 | 61.8 | 58.8 | 48.9–65.8 |
| Man, 5 ft 8 in (172.7 cm) | 68.4 | 67.2 | 67.5 | 69.6 | 55.2–74.3 |
| Man, 6 ft 0 in (182.9 cm) | 77.6 | 74.8 | 73.1 | 80.4 | 61.9–83.3 |
| Man, 6 ft 4 in (193.0 cm) | 86.8 | 82.4 | 78.8 | 91.2 | 68.9–92.8 |
| Woman, 5 ft 0 in (152.4 cm) | 45.5 | 49.0 | 53.1 | 45.5 | 43.0–57.8 |
| Woman, 5 ft 4 in (162.6 cm) | 54.7 | 55.8 | 58.5 | 54.3 | 48.9–65.8 |
| Woman, 5 ft 8 in (172.7 cm) | 63.9 | 62.6 | 64.0 | 63.1 | 55.2–74.3 |
| Woman, 6 ft 0 in (182.9 cm) | 73.1 | 69.4 | 69.4 | 71.9 | 61.9–83.3 |
All figures in kilograms, from the formulas above. The last column is WHO’s normal BMI range at that height (TRS 894, 2000).
Worked example
What does a worked example look like?
Take a man 5 ft 10 in tall, 10 inches over 5 feet. Devine gives 50 + 2.3 × 10, or 73.0 kg. Robinson gives 71.0 kg, Miller 70.3 kg and Hamwi 75.0 kg. At his height, 177.8 cm, a WHO normal BMI covers 58.5 to 78.7 kg, a range about 20 kg wide.
- A woman 5 ft 4 in tall: Devine 54.7 kg, Robinson 55.8 kg, Miller 58.5 kg, Hamwi 54.3 kg; normal BMI 48.9 to 65.8 kg
- On the Asian Indian range, 18.5 to 22.9, the same man’s normal weights are 58.5 to 72.4 kg, so Hamwi’s 75.0 kg sits above them
- In pounds, Hamwi’s original rule gives him 106 + 6 × 10 = 166 lb, about 75.3 kg
Origin
Why were ideal weight formulas created?
Mostly to dose medicines. Pai and Paloucek traced how the way the body handles certain drugs was found to follow ideal body weight, which led to the use of Devine’s equations. Robinson’s 1983 paper set out to determine ideal weight for drug dosage calculations, and Miller’s refined it. Hamwi’s older rule has no published method.
- Robinson and Miller fitted their formulas to Metropolitan Life Insurance height and weight tables
- Those tables came from insurance policy holders, measured in clothes and partly self-reported
- Pai and Paloucek found the formulas so alike that any one may be used to estimate ideal body weight
- Clinicians still use ideal body weight for some drug doses, feeding plans and ventilator settings
Using it
Should I use an ideal weight as my goal?
Treat it as one reference point. The formulas give a single number for a height, while a healthy weight is a range, and they ignore muscle, frame and where you carry fat. Look at the normal BMI range for your height and your waist alongside it, and set any goal with your doctor if you have a health condition.
- Peterson and colleagues showed the old formulas drift away from BMI at the short and tall ends
- Muscular people can be well above every formula and still lean
- For Asian Indian adults the normal BMI range tops out at 22.9, so at shorter heights some formulas sit above it
Versions
Why do sources give slightly different numbers?
Because the formulas are often rounded or converted. Robinson’s paper gives 51.65 kg plus 1.85 kg an inch for men, usually rounded to 52 and 1.9. Hamwi’s rule was in pounds. Miller’s constants usually appear as 56.2 plus 1.41, but a 2021 commentary lists 55.7 plus 1.39 for men.
- This calculator uses the rounded Robinson constants and the 56.2 + 1.41 version of Miller
- Rounding Robinson’s constants moves the result by under 1 kg up to 6 ft
- The two versions of Miller’s formula differ by under 1 kg up to 6 ft 4 in
Limits
Who should not rely on this ideal weight calculator?
Children and teenagers, because the formulas were built for adults, and anyone under 5 feet, where they are not defined. Pregnant women, people with a medical condition that affects weight and anyone with an eating disorder should talk to a doctor or registered dietitian before setting any weight goal.
- Very muscular people: the formulas do not see muscle
- The calculator takes heights from 120 to 230 cm; the formulas start at 152.4 cm
For coaches
How do coaches use ideal weight with clients?
Mostly as context, not as a target to chase. In Trainaq a client’s intake can record their goals, height and weight, weekly check-ins add weight and waist, and the progress view shows the weight trend, so you can talk about ranges and real change instead of a single number from a formula.
- The intake form can ask for measurements in metric or imperial units
- Clients see their own weight chart in the Trainaq app
- Calorie and macro targets sit on the client’s profile, with their history
Sources
Sources
- Pai MP, Paloucek FP. The origin of the “ideal” body weight equations. Ann Pharmacother. 2000;34(9):1066–1069.
- Robinson JD, Lupkiewicz SM, Palenik L, Lopez LM, Ariet M. Determination of ideal body weight for drug dosage calculations. Am J Hosp Pharm. 1983;40(6):1016–1019.
- Nowaczyk P, Murawa D, Połom K, et al. Analysis of sentinel lymph node biopsy results in colon cancer in regard of the anthropometric features of the population and body composition assessment formulas. Langenbecks Arch Surg. 2012;397(5):779–786. (Lists all four formulas in kilograms.)
- Chichester S, Holmes TM, Hubbard J. Ideal body weight: a commentary. Clin Nutr ESPEN. 2021;46:246–250.
- Peterson CM, Thomas DM, Blackburn GL, Heymsfield SB. Universal equation for estimating ideal body weight and body weight at any BMI. Am J Clin Nutr. 2016;103(5):1197–1203.
- WHO Consultation on Obesity. Obesity: preventing and managing the global epidemic. WHO Technical Report Series 894. Geneva: World Health Organization; 2000. Table 2.1.
- Misra A, Vikram NK, Ghosh A, et al. Revised definition of obesity in Asian Indians living in India. Diabetes Metab Syndr. 2025;19(1):102989.
FAQ
Ideal weight calculator FAQ
Which ideal weight formula is the most accurate?
None is accurate for an individual, because none measures you. They were fitted to old height and weight tables, and Pai and Paloucek concluded that any one of them may be used to estimate ideal body weight. Read the four together as a spread, beside the normal BMI range for your height.
Why does the ideal weight calculator give a range?
Because four formulas give four answers, and the gap between them shows how uncertain an ideal weight is. At 5 ft 10 in they span 70.3 to 75.0 kg for a man. The normal BMI range for the same height is wider still, about 20 kg, from 58.5 to 78.7 kg.
Do ideal weight formulas work for short people?
Not below 5 feet, where they are not defined, and less well near it. Peterson and colleagues found the old equations drift away from BMI at the short and tall ends of the height range. For a short adult, the normal BMI range for their height is the more useful reference, and the calculator shows it.
Is ideal body weight the same as lean body mass?
No. Ideal body weight is a reference weight for a height, and it includes fat. Pai and Paloucek note that it came to be read as a fat-free weight and used in place of lean body weight, a mix-up their review set out to clarify. The body fat calculator estimates lean mass directly.
Does ideal weight differ for Indian adults?
The formulas have no ethnic versions; Robinson’s and Miller’s came from American insurance tables. For Asian Indian adults, Indian guidance sets the top of the normal BMI range at 22.9 instead of 24.9, so the calculator shows that range too. At shorter heights, some formulas give more than that range allows.
