Standard adult BMI range
50.4 to 67.8 kg
111.0 to 149.5 lb
BMI 18.5 to 24.9 (WHO adult categories).
Health
Ideal Weight Calculator
See four historical ideal-weight formulas and BMI-based weight ranges side by side for your height.
Your details
Adults only. Your inputs stay in your browser and are never sent anywhere.
Four historical formulas, side by side
Historical estimates, not targets or a diagnosis. The Devine formula began as a drug-dosing rule.
| Formula | Kilograms | Pounds |
|---|---|---|
| Robinson (1983) | 57.4 kg | 126.6 lb |
| Miller (1983) | 59.8 kg | 131.9 lb |
| Devine (1974) | 56.9 kg | 125.5 lb |
| Hamwi (1964) | 56.6 kg | 124.8 lb |
Across the four formulas: 56.6 to 59.8 kg (124.8 to 131.9 lb).
Weights for a BMI of 18.5 to 24.9
Asian-population range
50.4 to 62.3 kg
111.0 to 137.4 lb
BMI 18.5 to 22.9 (WHO expert consultation, Asian populations).
BMI is a screening ratio. It does not measure body fat and is not a diagnosis.
ChangelogHow we test this calculatorEmbed this calculator
How this calculator works
For 5 ft 5 in (165.0 cm), four old formulas land between 56.6 kg and 59.8 kg. They are historical estimates, not a target.
- Step 1Measure your height5 ft 5 in (165.0 cm)converted to inches at 2.54 cm per inch
- Step 2Count inches over 5 ft4.96 inevery formula starts from a base weight at 5 ft
- Step 3Add a weight per inch56.9 kgDevine shown here; each formula has its own base and per-inch amount
The formulas are straight lines: a base weight at 5 ft, plus a fixed amount for each inch above it. Men and women have different constants. Nothing else about you is used.
Where these numbers came from
- Hamwi, 196456.6 kgA quick rule of thumb for clinicians, written in pounds.
- Devine, 197456.9 kgWritten to help dose a drug, gentamicin. It was never meant as a health goal.
- Robinson, 198357.4 kgA later fit to height-weight tables, again for drug-dose work.
- Miller, 198359.8 kgAnother refit of the same tables, with a smaller per-inch step.
Worked example
- Inches over 5 ft
x = height in inches − 60- Devine (female)
weight in kg = 45.5 + 2.3 × x
- xinches over 5 ft 4.96
- 45.5base weight at 5 ft 45.5 kg
- Height in inches165 ÷ 2.5464.96 in
- Inches over 5 ft64.96 − 604.96
- Added for those inches2.3 × 4.9611.4 kg
- Devine estimate45.5 kg + 11.4 kg56.9 kg (125.5 lb)
The other three formulas use the same steps with different constants.
Reading your result
- BMI 18.5 to 24.950.4 to 67.8 kg111.0 to 149.5 lb. The standard adult range used by the WHO.
- BMI 18.5 to 22.950.4 to 62.3 kg111.0 to 137.4 lb. A lower top end discussed for Asian populations, including India.
The BMI range comes from weight = BMI × height in metres squared. It gives a span of weights, not one ideal figure, and the formula results need not fall inside it.
What the result leaves out
- Not a goalA formula result is not a weight to aim for.
- Body make-upMuscle, bone size, body fat, age and health conditions are not used.
- Adults onlyThese are adult formulas. They do not cover children, teenagers or pregnancy.
- Below 5 ftThe formulas start at 5 ft. Shorter heights run along the same line and can look unrealistic.
Below 5 feet
The formulas add weight per inch over 5 ft, so under 5 ft the arithmetic simply runs backwards.
This calculator still shows those results for heights from 4 ft, with a warning. For example, the Devine formula for a woman of 4 ft gives 17.9 kg, which is not a meaningful weight. The BMI ranges are unaffected.
Weight is only one measure
These formulas use height and sex only. Body fat, energy needs and life stage tell you things they cannot.
The BMI calculator shows where a weight falls in the WHO adult categories, including the lower Asian cut-offs. The body fat calculator estimates composition from tape measurements, and the BMR and TDEE calculator estimates daily energy.
During pregnancy, a different guide applies; see the pregnancy weight gain calculator.
Common mistakes
Mistake: Treating the "ideal" label as a target to hit.
Instead: Read it as a historical estimate, and talk to a health professional about weight goals.
Mistake: Averaging the four results into one number.
Instead: Look at the spread. It shows how uncertain these formulas are.
Mistake: Using the Asian BMI range without knowing why.
Instead: It is one more way to read BMI for some populations. Ask a clinician which applies to you.
Mistake: Using the result for a child or teenager.
Instead: These formulas are for adults only.
This tool is for general information and is not medical advice, diagnosis or treatment. Talk to a qualified healthcare professional about your situation.
Checking the method
A separate script recomputes every test case two ways, in exact fractions and in a rearranged floating-point form, and checks each value.
Read how we test our calculators, or browse more health calculators.
Frequently asked questions
What is an ideal weight formula?
It is a short equation that turns height and sex into a weight estimate. The four used here date from 1964 to 1983 and were written for clinicians, not as health targets.
Why do the four formulas give different answers?
Each uses its own base weight at 5 ft and its own amount per extra inch. The differences show how rough the estimates are.
Where did the Devine formula come from?
It was published in 1974 to help estimate drug doses, such as gentamicin. It was never meant to say what a person should weigh.
Is the result a weight I should aim for?
No. It is a historical estimate. It ignores muscle, bone size, body fat, age and health conditions. Talk to a health professional about weight goals.
What is the BMI healthy weight range?
It is the span of weights whose BMI falls between 18.5 and 24.9 at your height. BMI is a screening ratio and does not diagnose anything.
Why is there a separate range for Asian populations?
A WHO expert consultation found that health risks can rise at lower BMI in Asian populations. This page shows 18.5 to 22.9 as a variant for comparison.
What happens below 5 ft?
The formulas are defined per inch over 5 ft. Below that, this tool extends the same line and shows a warning, so very short heights can give unrealistically low figures.
Can I use it for children or during pregnancy?
No. These are adult formulas and do not cover children, teenagers or pregnancy.
Sources and methodology
The formulas are standard time-value-of-money results. We check every figure against golden values worked out independently, by closed form and by month-by-month simulation; see the methodology.
- Determination of ideal body weight for drug dosage calculations (Robinson et al., 1983), American Journal of Hospital Pharmacy (accessed 22 Oct 2026)
- The origin of the "ideal" body weight equations (Pai and Paloucek, 2000), Annals of Pharmacotherapy (accessed 22 Oct 2026)
- Obesity and overweight (fact sheet), World Health Organization (accessed 22 Oct 2026)
- Appropriate body-mass index for Asian populations and its implications for policy and intervention strategies, The Lancet / WHO Expert Consultation (accessed 22 Oct 2026)
- Dietary Guidelines for Indians, ICMR-National Institute of Nutrition (accessed 22 Oct 2026)
Written and maintained by Nitin Raturi, a software engineer (about the author). Last reviewed 22 Oct 2026; next review due by . Found an error? Tell us.
Changelog
- : Initial release.