Ideal Weight Calculator
Healthy-weight range from WHO BMI categories + Devine, Robinson, Miller, and Hamwi formulas (heights ≥152 cm / 5 ft).
Result
- Devine (1974)most widely used in pharmacy / drug dosing70.5 kg
- Robinson (1983)68.9 kg
- Miller (1983)often the highest figure of the four68.7 kg
- Hamwi (1964)used in older nursing references72.0 kg
- Range across 4 formulas68.7 kg – 72.0 kg
- Underweight (BMI < 18.5)< 56.7 kgNote
- Healthy (BMI 18.5 – 24.9)56.7 kg – 76.3 kgHealthy
- Overweight (BMI 25.0 – 29.9)76.6 kg – 91.6 kgBorderline
- Obese (BMI ≥ 30)≥ 91.9 kgHigh risk
- Height175.0 cm (68.9 in)
- DisclaimerRanges shown are general adult guidelines based on WHO BMI categories. Ideal weight depends on body composition, age, muscle mass, and other factors. Consult a healthcare provider for personalized advice. For children/adolescents, use age-and-sex-specific growth charts.Note
How to use this calculator
- Pick your sex.
- Enter your height in cm or inches.
- Read the WHO BMI healthy range first — that's the modern guidance.
- For heights ≥ 5 ft, also compare the four classic formulas (Devine / Robinson / Miller / Hamwi).
About this tool
"Ideal weight" formulas (Devine, Robinson, Miller, Hamwi) are clinical-era heuristics designed for medication dosing in adults ≥5 ft tall — not modern definitions of healthy weight. They give different answers for the same height because each was calibrated against a different population and goal. Devine (1974) remains the most widely used in pharmacy. None of them account for muscle mass, body composition, age, or sex differences in fat distribution. The WHO BMI band (18.5 – 24.9 kg/m²) is the modern population-level reference — it scales with height² and is shown above for every input. For a single weight target, use the average of the four formulas (heights ≥152 cm only). For a body-composition view, see the Body Fat Calculator. **Not medical advice.**
What this calculator does
This calculator returns a healthy-weight range for your height using two anchors. First, the modern WHO BMI band (18.5 – 24.9 kg/m²), which scales smoothly with height squared and is medically valid at every adult height. Second, for heights at or above 152 cm (5 ft), it also computes the four classic clinical-pharmacy formulas — Devine, Robinson, Miller, and Hamwi — and shows the range across them as a single-point cross-check. Below 5 ft those four formulas degenerate to a constant and are intentionally suppressed.
How it works — the formula
Devine: 50 + 2.3 × (h_in − 60) [male]; 45.5 + 2.3 × (h_in − 60) [female]h_in is height in inches above 60. Devine 1974 returns kilograms and is the most widely cited "ideal body weight" formula in clinical pharmacy. Robinson 1983 (52 + 1.9·… male; 49 + 1.7·… female), Miller 1983 (56.2 + 1.41·…; 53.1 + 1.36·…), and Hamwi 1964 (48 + 2.7·…; 45.5 + 2.2·…) follow the same shape with slightly different constants. The modern population-level reference is the WHO BMI healthy band of 18.5–24.9 kg/m², shown alongside.
Worked examples
- Inputs:
- sex = male, height = 70 in
- Output:
- Devine ≈ 73.0 kg; WHO healthy band ≈ 58.7–79.0 kg
Devine sits comfortably in the upper half of the WHO healthy band — typical for adult males of average frame.
- Inputs:
- sex = female, height = 65 in
- Output:
- Devine ≈ 57.0 kg; WHO healthy band ≈ 50.4–67.8 kg
WHO band gives a 17 kg envelope where the Devine point estimate is one workable target inside it.
- Inputs:
- sex = female, height = 145 cm
- Output:
- WHO healthy band ≈ 38.9–52.4 kg only — Devine/Robinson/Miller/Hamwi suppressed
The four classic formulas were never validated below 152 cm; suppressing them is the deliberate fix for a prior bug that returned a flat ≈49 kg.
When to use this vs other tools
Ideal-weight formulas answer "what should I weigh?". For other body-composition or clinical questions, reach for a more specific tool.
- BMI Calculator
Use when you have a known weight and want the WHO category (underweight / normal / overweight / obese). Ideal-weight goes the other way: it asks what weight matches a healthy BMI for your height.
- Body Fat Calculator
Use when muscle mass is high (athletes, weight-lifters). Body-fat percentage separates lean tissue from adipose tissue — the four ideal-weight formulas ignore that distinction entirely.
- Lean Body Mass Calculator
Use for clinical drug-dosing where the dose scales on lean mass (chemotherapy, anaesthesia). Lean mass is more pharmacokinetically relevant than total or "ideal" body weight.
- Calorie Calculator (TDEE)
Use once you have a target weight to compute the daily calorie intake needed to reach and maintain it. Pair the target from this tool with a TDEE deficit / surplus.
Authority note
The WHO BMI band is the modern population-level anchor used by this calculator at every height. Devine 1974, Robinson 1983, Miller 1983, and Hamwi 1964 are the clinical-pharmacy heuristics shown as supplementary point estimates for heights ≥ 152 cm only.
Limitations
- Devine, Robinson, Miller, and Hamwi were calibrated for adults ≥5 ft and degenerate to a constant below that height — never extrapolate.
- None of these formulas account for muscle mass, frame size, age, or fat distribution.
- Pediatric and adolescent reference is the CDC/WHO sex-and-age-specific growth chart, not these formulas.
- Pharmacy dosing standards vary by country and drug — confirm the IBW formula your protocol expects.
"Ideal" weight is a clinical heuristic, not a personal target. This calculator does not provide medical advice — consult a clinician for an individualized assessment.