Answer: Enter your values and the Ideal Weight Calculator returns the exact result instantly — formula, worked example, and a plain-English explanation are included below the tool.
Find your healthy weight range
Enter your height in centimeters and select your sex at birth, and the calculator shows three established ideal body weight (IBW) formulas side by side — Devine, Robinson, and Miller — plus the weight range that corresponds to a healthy Body Mass Index of 18.5 to 24.9 for your height. All three formulas are decades-old clinical standards still used for drug dosing and nutritional assessment; the BMI range gives a population-level cross-check.
The formulas share a common structure: a base weight at 5 feet (152.4 cm) plus a fixed number of kilograms per inch over 5 feet. Devine uses 50 kg + 2.3 kg/inch for men and 45.5 + 2.3 for women; Robinson uses 52 + 1.9 and 49 + 1.7; Miller uses 56.2 + 1.41 and 53.1 + 1.36. This calculator implements exactly those coefficients.
Devine (1974) was originally derived for medication dosing and remains the most cited. Robinson (1983) and Miller (1983) were later revisions arguing Devine overestimated weights at taller heights — notice Miller's much smaller per-inch increment produces lower results for tall people. At 175 cm (about 9.1 inches over 5 feet), a man gets roughly 71 kg from Devine, 69 kg from Robinson, and 69 kg from Miller; the calculator displays all three so you can see the spread rather than a single possibly misleading number.
The BMI healthy range is computed straight from the BMI definition: weight = height(m)² × BMI. At 175 cm the range 18.5–24.9 corresponds to about 57–76 kg — noticeably wider than any single IBW figure, which is why clinicians treat IBW as a reference point, not a target.
Ideal body weight formulas ignore body composition: a muscular athlete and a sedentary person of the same height get the same number, even though their healthy weights differ substantially. BMI has the same limitation — it uses only height and total mass. Both tools were designed for populations and quick screening, not individual diagnosis.
In clinical practice, IBW survives mainly for dosing of certain medications and for setting ventilator tidal volumes, where a formula anchored to height is more useful than actual weight. For general health goals, the BMI range plus waist circumference and body-fat measures give a fuller picture than any single formula.
Note also that the formulas were developed in Western populations; applying them elsewhere can shift results slightly. None of the three accounts for age beyond adulthood.
| Formula | Male @ 175 cm | Female @ 165 cm | Basis |
|---|---|---|---|
| Devine (1974) | 70 kg (155 lb) | 57 kg (125 lb) | Drug dosing reference |
| Robinson (1983) | 69 kg (152 lb) | 57 kg (126 lb) | Revision of Devine |
| Miller (1983) | 69 kg (152 lb) | 58 kg (127 lb) | Revision of Devine |
| BMI 18.5–24.9 range | 57–76 kg | 50–68 kg | Population screening |
The table shows the calculator's output for the default 175 cm male input. Inches over 5 ft = (175 − 152.4) ÷ 2.54 = 8.86. Devine: 50 + 2.3 × 8.86 = 70.4 kg (about 70 kg, 155 lb). Robinson: 52 + 1.9 × 8.86 = 68.8 kg. Miller: 56.2 + 1.41 × 8.86 = 68.7 kg. BMI range: 1.75² × 18.5 = 56.7 kg to 1.75² × 24.9 = 76.3 kg.
The calculator takes height in centimeters because that is the clinical standard worldwide, but the formulas were built on inches. The conversion is exact: 1 inch = 2.54 cm and 5 feet = 152.4 cm. Common height equivalents: 160 cm ≈ 5 ft 3 in, 168 cm ≈ 5 ft 6 in, 175 cm ≈ 5 ft 9 in, 183 cm ≈ 6 ft 0 in. The internal math converts your metric input to inches over five feet before applying each formula's coefficients.
Frame size is the classic caveat: the original formulas assume a medium frame, and older clinical guides adjusted ±10% for small or large frames measured by wrist circumference against height. This calculator deliberately shows the unadjusted formula outputs alongside the wide BMI band rather than pretending to a single precise answer.
For weight goals, move gradually. If you're well outside the healthy BMI range shown alongside the formulas, a target of losing or gaining 5–10% of body weight over six months is a clinically common first milestone — small enough to sustain, meaningful enough to move health markers.
Which ideal weight formula is most accurate?
None is definitively 'accurate' — they are estimates from height alone. Devine is the most widely used clinically; Robinson and Miller were later revisions. For a broader picture use the healthy BMI range this calculator also shows, and remember none account for muscle mass, age, or frame size.
What is the Devine formula?
Devine (1974): men = 50 kg + 2.3 kg per inch over 5 feet; women = 45.5 kg + 2.3 kg per inch over 5 feet. It was developed as a medication-dosing reference and remains the standard IBW formula in clinical settings.
Is ideal body weight the same as a healthy weight?
No. IBW formulas give a single estimate from height; healthy weight is a range (the BMI 18.5–24.9 band) and depends on body composition, sex, age, and ethnicity. Treat IBW as one reference point among several.
Do these formulas work for children?
No. They assume adults and anchor at 5 feet tall. Children and adolescents are assessed with age- and sex-specific BMI percentile charts, not IBW formulas.
Why do the three formulas differ?
They were derived from different reference populations and assumptions about how weight scales with height. Miller uses the smallest per-inch increment (1.36–1.41 kg), so it returns the lowest values for tall people; Devine's 2.3 kg/inch yields the highest for the same height.