Ideal Weight Calculator
Calculate your ideal body weight using four established medical formulas and find your target weight range.
How to use this ideal weight calculator
- 1Enter your sex and height in inches (5 ft 8 in = 68 in).
- 2The four formulas provide a range — treat the result as a zone, not a precise target.
- 3These formulas assume average frame size. Add 10% for large frame, subtract 10% for small.
- 4Combine with BMI healthy weight range for a more complete picture.
- 5Consult a healthcare provider to set an appropriate weight goal for your individual health situation.
How it's calculated
Devine (men): 50 + 2.3 × inches over 5 ft. Women: 45.5 + 2.3 × inches over 5 ft. Each formula uses a base weight at 5 ft with a per-inch increment.
About the Ideal Weight Calculator
Ideal weight formulas have a fascinating history rooted not in fitness or aesthetics but in medicine. The Devine formula, the most widely used, was published in 1974 by Dr. B.J. Devine as a method for pharmacologists to calculate appropriate drug doses — particularly for medications where dosing based on actual body weight in obese patients would cause toxicity. The formula was a clinical tool that found its way into fitness culture and weight management discussions.
The limitations of ideal weight formulas are fundamental — they assume a fixed relationship between height and weight that applies to everyone, ignoring the enormous variation in skeletal frame size, muscle mass, and body composition. A naturally narrow-framed person may feel best at the lower end of the range; a broad-framed, naturally muscular person may be at their ideal composition significantly above it. The ideal implied by these formulas is a statistical average, not a biological destination.
For practical weight goal setting, combining multiple metrics gives a more complete target: the healthy BMI range (18.5–24.9), the ideal weight formula range (as a reference point), and a target body fat percentage based on sex and goals. The convergence of these estimates — where all three overlap — represents a reasonable individual healthy weight zone.
Perhaps most importantly, weight goals should be functional rather than numerical. A meaningful question is not what you should weigh but at what weight you feel energetic, move well, have healthy metabolic markers, and can maintain without unsustainable restriction. This functional definition of ideal weight is more useful than any formula's output.
Frequently asked questions
Which ideal weight formula is most accurate?
No single formula is universally most accurate — each was developed for different purposes. The Devine formula is most widely used in clinical medicine, particularly for medication dosing (it calculates dosing weight for many IV medications). Robinson and Miller attempted to improve on Devine's original work. Hamwi is commonly used by dietitians. None account for frame size, age, or body composition. Use the range across all four formulas as a target zone rather than any single output as a precise ideal.
Is ideal weight the same as healthy weight?
Not necessarily. Ideal weight formulas were developed primarily for clinical pharmacology (calculating drug doses based on lean body mass) rather than defining optimal health. A healthy weight range from BMI (18.5–24.9) covers a broader range than most ideal weight formulas. Individual frame size, muscle mass, and body composition mean that a weight above or below the formula results can be perfectly healthy. Athletes with high muscle mass typically exceed ideal weight formula outputs while being in excellent health.
What if I have never weighed what the formula says?
These formulas represent statistical averages from population studies, not biological requirements. Many people maintain excellent health at weights above or below all four formula outputs. If you have maintained a stable weight for years without trying, are metabolically healthy (normal blood pressure, blood sugar, cholesterol), physically active, and feel well, your stable weight may simply be your personal healthy weight. Weight naturally varies throughout adult life. The formulas provide reference points; clinical health markers and functional capacity matter more.
Do ideal weight calculations apply to all ethnicities?
The ideal weight formulas were developed primarily from European-ancestry populations and may not apply equally to other ethnic groups. Research shows Asian populations tend to have higher body fat percentages at equivalent weights and heights compared to European populations, suggesting lower weight targets may be appropriate. As with BMI, these formulas are best understood as rough reference points requiring individual interpretation rather than universal prescriptions.