Ideal Weight Calculator
Ideal body weight formulas were built for clinical purposes — drug dosing, ventilator settings — not for personal goal setting. This calculator applies the Devine formula so you can see that reference figure and understand why it should be read alongside a healthy weight range rather than instead of one.
Inputs
Result
70.5 kg
155.3 lb (Devine formula)
How the ideal weight calculator works
Devine formula: men 50 kg + 2.3 kg per inch over 5 feet; women 45.5 kg + 2.3 kg per inch over 5 feet.
Everything below 5 feet uses the base figure, which is one reason the formula behaves poorly at short statures.
Related formulas — Robinson, Miller and Hamwi — use different constants and can differ by several kilograms for the same person.
Worked example: a man 5 ft 10 in tall
- Inches over 5 feet: 10.
- Devine: 50 + (2.3 × 10) = 73 kg.
- For a woman of the same height: 45.5 + 23 = 68.5 kg.
- The healthy BMI range at 1.78 m is 58.6–78.9 kg, so the Devine figure sits mid-range.
- At 6 ft 4 in, Devine gives 87.2 kg while the BMI range reaches 100 kg — the formula drifts low for tall people.
Common mistakes to avoid
Treating the output as a personal goal
It is a population reference used for dosing calculations. A healthy weight range or a body composition target is far more appropriate for individuals.
Comparing outputs from different formulas
Devine, Robinson, Miller and Hamwi disagree by design. Pick one and stay with it rather than choosing whichever is most flattering.
Applying it to children or athletes
The formula was derived from adults of average build and has no validity for growing children or heavily muscled adults.
Frequently asked questions
What is the Devine formula?
A 1974 clinical formula for ideal body weight based only on sex and height, originally created to standardise drug dosing.
Why does it give a lower figure than my healthy range?
It produces a single mid-range point, and it drifts low at tall statures because it adds a fixed amount per inch rather than scaling with height squared.
Which formula is most accurate?
None is accurate for individuals — they are population averages. Robinson tends to give slightly lower values than Devine, Hamwi slightly higher.
Should I use ideal weight or BMI?
Use the healthy weight range from BMI for personal goals, and reserve ideal body weight for the clinical contexts it was designed for.
Does frame size adjust the result?
Some clinicians add or subtract about 10% for large or small frames, usually judged by wrist circumference or elbow breadth.
Related calculators
Healthy Weight Calculator
Healthy weight range for your height based on BMI 18.5–24.9.
BMI Calculator
Body Mass Index from height and weight, with WHO category.
Lean Body Mass Calculator
Estimate fat-free mass using the Boer formula.
Body Surface Area Calculator
Mosteller BSA, widely used for dosing.
Body Fat Calculator
Estimate body fat percentage with the US Navy method.