Ideal Weight Calculator
Three standard answers — Devine, Robinson, and the healthy-BMI band — because one number was never the truth.
Find your healthy weight range
Where "ideal weight" formulas come from
The famous formulas weren't invented for dieting. The Devine formula (1974) — 50 kg + 2.3 kg per inch over five feet for men, 45.5 kg base for women — was created to dose medications, and hospitals still use it for exactly that. Robinson (1983) refined it against population data. The healthy BMI range (18.5–24.9) is the modern screening band. This calculator shows all three because they answer slightly different questions.
A worked example
A 5'10" man: Devine says about 161 lb, Robinson about 156 lb, and the healthy-BMI band runs roughly 129–173 lb. Notice the band is 44 pounds wide — that's the honest answer. A muscular 185-lb man at 5'10" can be in excellent health while sitting above every formula; a sedentary 150-lb man can carry too much visceral fat while looking "ideal" on paper.
What to actually do with this number
Treat the range as a sanity check, not a target etched in stone. Better health markers than scale weight: waist circumference (under roughly half your height in inches), strength and stamina trends, blood pressure, and lab work. If your weight sits far outside the band in either direction, that's worth a conversation with a doctor — who will look at the whole picture, not a 1974 dosing formula. Pick goals by how you feel and perform, and let the scale be one witness among several.
Frequently asked questions
Why do the formulas disagree with each other?
They were fit to different datasets and purposes decades apart. Disagreement of 5–10 pounds is normal and meaningless — that's why the BMI range is shown as a band, not a point.
Is ideal weight different for athletes?
Substantially. Muscle is dense, so strength athletes routinely exceed every formula while being lean. Body-fat percentage and waist measurement describe athletic bodies far better.
Does age change ideal weight?
Somewhat — modest weight gain into middle age appears benign, and very low weight becomes riskier in older adults (muscle loss). The formulas ignore age entirely; doctors don't.
What's a realistic pace to reach a healthy weight?
About 0.5–1% of body weight per week, via a moderate calorie deficit with adequate protein and resistance training. Slower is fine; sustainable beats fast every time.