Discover your personalized ideal body weight using four established clinical formulas. Get a science-backed target range so you know exactly what to aim for on your fitness journey.
Ideal body weight (IBW) formulas estimate a target mass from height using clinical equations developed for drug dosing and nutrition planning — not aesthetic ideals. Common methods include Devine (1974), Robinson (1983), Miller (1983), and Hamwi (1964), each adding a per-inch increment above five feet (152 cm) to a sex-specific base. Devine gives men IBW (kg) = 50 + 2.3 × (height in inches − 60); women use 45.4 + 2.3 × (height − 60). Results for a 170 cm adult often cluster near 61–68 kg across formulas, with a spread of several kilograms reflecting different calibration cohorts. IBW differs from BMI healthy-range weight, which spans roughly 18.5–24.9 BMI for a given height. Frame size, athletic build, and ethnicity are not fully represented in these legacy formulas. Ideal weight differs from BMI healthy-range weight, which spans a broader band for the same height. Use the cluster of formula results as a reference range rather than a single mandatory target.
Worked example: A 170 cm (66.9 in) man via Devine: IBW = 50 + 2.3 × (66.9 − 60) = 50 + 15.9 ≈ 66 kg. The same height via Robinson might read near 64 kg — the range between formulas is normal.
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What the formulas mean and how to use this number.
Different formulas give different results because "ideal" depends on body frame, muscle mass, and lifestyle. The range shown reflects the spread across four validated formulas — your personal optimum lives somewhere in this range.
These formulas were developed for general populations, not athletes. A well-muscled person's ideal weight may be 5–10 kg higher than the formula suggests. Pair this with body fat percentage for a more complete picture.
Aim for 0.5 kg/week of fat loss — any faster risks muscle loss and metabolic adaptation. A structured resistance training program ensures the weight you lose is fat, not the muscle that gives you shape.
Formula ideal weight is a reference band for clinical and planning contexts, not a mandate for everyone. Frame size, muscle mass, and ethnicity are poorly captured. Pair IBW with body composition, performance goals, and how you feel at different weights.
Ideal weight explained.
They are accurate reference ranges for average-build adults. They don't account for muscle mass or bone density. A bodybuilder may healthily weigh 15–20 kg above the formula result. Use them as a starting point, not an absolute target.
Neither is perfect in isolation. BMI uses your current weight; ideal weight formulas predict a target. Combine both with body fat percentage and waist-to-height ratio for the most comprehensive health picture.
Each formula was derived from a different population study with different methodologies. The Hamwi formula was developed for clinical medication dosing. Devine was for pharmacokinetics. Robinson and Miller aimed for broader health applications. The range between them captures this real-world variability.
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Browse All Tools →This calculator gives a general estimate for education and planning. It is not a medical diagnosis and does not replace advice from a qualified healthcare professional. Talk to your doctor before acting on these results — especially if you are pregnant, under 18, or managing an existing medical condition.