Ideal Weight Calculator
Find your ideal body weight using four clinically established formulas — Devine, Robinson, Miller, and Hamwi — plus a healthy BMI weight range. Enter your height and sex to see results instantly.
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Understanding Ideal Weight
The Devine Formula — a brief history
The Devine formula was published by B.J. Devine in 1974 and was not originally intended as a fitness target. It was developed to estimate ideal body weight for the purpose of calculating medication dosages — particularly for drugs where the therapeutic dose depends on lean body mass. Despite its clinical origins, it became the most widely quoted ideal weight formula and is still used in pharmacy, nephrology, and anesthesiology today.
Why do the formulas give different numbers?
Each formula was derived from a different sample population at a different time. Devine (1974) and Hamwi (1964) predate modern nutrition epidemiology. Robinson and Miller (both 1983) were attempts to update the estimates using more recent data. Because the formulas used different reference populations, sex-specific base weights, and per-inch increments, they produce a spread of results. This spread is actually useful — it gives you a realistic range rather than false precision.
Healthy BMI range — what it means
A Body Mass Index between 18.5 and 24.9 is classified as healthy by the World Health Organization and most national health authorities. The BMI weight range shown in this calculator is the range of body weights that produce a BMI in that band for your specific height. BMI has well-known limitations — it does not account for muscle mass or fat distribution — but remains a practical population-level screening tool and a useful complement to formula-based estimates.
Beyond the number
No formula can capture every aspect of a healthy body. Muscle mass, bone density, age, ethnicity, and metabolic health all matter but cannot be derived from height and sex alone. The results from this calculator are best used as a rough reference range, not a precise target. If your current weight falls within the range of estimates, you are likely at a healthy weight. If you are significantly outside the range, consider speaking with a healthcare provider who can assess your full health picture.
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BMI Calculator
Calculate your Body Mass Index and healthy weight range using metric or imperial units.
Open calculator →Body Fat Calculator
Estimate your body fat percentage using the U.S. Navy method and find your lean mass.
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Find your Total Daily Energy Expenditure and get calorie targets for weight loss or muscle gain.
Open calculator →FAQ
Which ideal weight formula is most accurate?
No single formula is universally most accurate because ideal weight depends on individual factors like muscle mass, bone density, and body composition. The Devine formula (1974) is the most widely cited in clinical settings and is still used to calculate medication dosing. The BMI range (18.5–24.9) is the most commonly used population standard. Using multiple formulas together — as this calculator does — gives a realistic range rather than a single number.
What does ideal weight actually mean?
Ideal weight is a statistical estimate of the body weight associated with good health for a given height and sex. It is not a single perfect number but a range. Formulas like Devine and Robinson were originally developed for clinical uses such as drug dosing, not personal fitness. A healthy weight is best understood as a range where your risk of weight-related disease is low and you feel well.
Is BMI a good measure of ideal weight?
BMI (Body Mass Index) is a simple screening tool that correlates height and weight. A BMI between 18.5 and 24.9 is considered healthy for most adults. However, BMI does not distinguish between fat and muscle mass, and it can misclassify muscular individuals as overweight or older adults with low muscle as healthy. It is best used alongside other measures such as waist circumference and body fat percentage.
How can I reach my ideal weight?
The most evidence-backed approach is a modest calorie deficit (250–500 kcal/day below your TDEE) combined with sufficient protein intake (0.7–1 g per lb of body weight) to preserve muscle, and regular resistance training. Sustainable fat loss is typically 0.5–1 lb per week. Rapid weight loss often leads to muscle loss and metabolic adaptation. Use a TDEE calculator to find your calorie target, then adjust over weeks based on results.
What if I am under 5 feet tall?
The Devine, Robinson, Miller, and Hamwi formulas all use inches above 5 feet (60 inches) as their variable. For heights below 5 feet, excess inches becomes negative, which reduces the ideal weight estimate below the base value. This calculator handles sub-5-foot heights correctly. Results are still useful as estimates, though the formulas were primarily validated for heights at or above 5 feet.