Ideal Weight Calculator
Estimate ideal body weight using five clinical and historical formulas: Devine, Robinson, Miller, Hamwi, and the healthy-BMI range. See where each formula puts you.
How to Use
- Pick your sex (formulas differ by sex).
- Enter your height. Most formulas were developed in imperial units (inches over 5 feet); the calculator handles either.
- Read the ideal weight estimates from each of the five formulas.
- The healthy BMI range gives you a window of "normal" weights rather than a single number.
- Use these as guides only — context matters more than any single formula.
- Talk to a clinician for medical decisions; this is for general orientation.
Formulas
Frequently Asked Questions
Why are there five different formulas?
Each was developed for a different purpose by a different researcher. <strong>Hamwi (1964)</strong> was the original, derived for U.S. life-insurance tables. <strong>Devine (1974)</strong> was developed for medication dosing. <strong>Robinson (1983)</strong> and <strong>Miller (1983)</strong> updated Devine with new population data. The <strong>healthy BMI range</strong> (BMI 18.5–24.9) gives a window rather than a point estimate. They typically agree within 5–10 lb of each other.
Which formula should I trust most?
For medication dosing in clinical settings, Devine is the historical standard (still widely used). For general fitness or weight goals, the healthy BMI range is more flexible and less prescriptive. None of these formulas account for body composition — a muscular person legitimately exceeds their 'ideal' weight, and a sedentary person within ideal weight may still be unhealthy.
Are these meant for me as an individual?
They're population-level estimates that don't know about your bone density, muscle mass, or build. Most adults are 'within range' of multiple formulas; falling slightly above or below isn't medically meaningful on its own. Take this as orientation, not a target weight.
What if my ideal weight from BMI seems too low?
If you're muscular, the BMI range will underestimate the right weight for you — your body composition includes more lean tissue than the formulas assume. Consider body-fat percentage (Body Fat Calculator) for a more individual measure. If you're not muscular, the lower end of the BMI range is generally where mortality data suggests is healthiest.
Why use these for medication dosing?
Many drugs (especially in obese patients) are dosed by ideal body weight rather than actual weight because fat tissue doesn't take up the drug the way lean tissue does. Devine and similar formulas give a clinically-relevant 'lean-equivalent' weight that produces correct dosing without overdosing fat-tissue-sparing drugs.
What's adjusted body weight?
A clinical concept used when patients exceed ideal body weight by 30%+. AdjBW = IdealBW + 0.4 × (ActualBW − IdealBW). Used for some drug dosing where neither pure ideal nor pure actual weight is appropriate. Not part of this calculator's output but worth knowing for medical contexts.
Common Use Cases
General fitness goal-setting
Pick a target weight using the formula that best matches your build and goals.
Insurance underwriting
Many life-insurance medical exams use ideal weight ranges as part of their tables; knowing your number in advance helps anticipate ratings.
Pre-surgery medication dosing
Anesthesiologists and pharmacists often use ideal body weight (Devine formula specifically) to calculate doses for patients above ideal weight.
Pediatric → adult transition
Adolescent weight charts give way to adult ideal-weight formulas in the late teen years; this provides a starting reference.
Sports weight classes
Wrestlers, boxers, and MMA fighters use formulas like these as part of weight-cutting target setting (consult a sports physician).
Eating disorder recovery
Therapeutic weight-restoration goals are often set in reference to ideal-weight formulas; always work with a treatment team rather than self-calibrating.
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