Ideal Weight Calculator
Estimate a reference ideal weight range based on height and sex, using the widely used Devine formula.
How this calculator works
The Devine formula, originally developed for medication dosing, is one of the most commonly cited reference formulas for ideal body weight.
This is a population reference, not a personal target — body composition and frame size vary widely.
Limitations of ideal weight formulas
These formulas don't account for muscle mass, bone structure, or individual body composition, so they're best treated as a general reference point rather than a personal goal.
Comparing ideal weight formulas
The Devine formula used here is one of several reference formulas — others include the Robinson, Miller, and Hamwi formulas, each derived slightly differently and producing modestly different results. All are population-level references rather than individualized targets.
Frame size, muscle mass, and individual body composition all mean a healthy weight for one person can differ meaningfully from these formula-based estimates — they're best used as a general reference point rather than a strict target.
A worked example
A man who is 180cm tall: that's about 70.9 inches, or 10.9 inches over 5 feet. Using the Devine formula: 50 plus (2.3 times 10.9) equals 50 plus 25.1, or 75.1kg, about 165.6 lbs.
For a woman at the same height: 45.5 plus (2.3 times 10.9) equals 45.5 plus 25.1, or 70.6kg, about 155.6 lbs — illustrating the roughly 10-15 lb difference the formula applies between sexes at the same height.
Other formulas for ideal weight
The Devine formula used here is one of several reference formulas — Robinson, Miller, and Hamwi formulas exist with slightly different constants and produce modestly different results, though all follow the same general height-based approach.
None of these formulas account for frame size, muscle mass, or individual body composition, which is why they're best used as a rough reference point rather than a precise personal target.
Frequently asked questions
Is this formula still considered accurate?
It's a commonly used clinical reference, particularly for medication dosing, but it's a population average and doesn't account for individual differences in build or muscle mass.
Why do different ideal weight formulas give different results?
Each formula was derived from different population data and assumptions decades ago — none is definitively 'correct,' and all should be treated as general reference points rather than precise targets.
Is BMI or ideal weight formula more useful?
Both have similar limitations — neither accounts for muscle mass or individual body composition, so pairing either with other measures like body fat percentage gives a fuller picture.
Why do different ideal weight formulas give different results?
Each formula (Devine, Robinson, Miller, Hamwi) was derived from different population data and uses slightly different constants, so results typically vary by a few kilograms between formulas for the same height.