Ideal Weight Calculator
Find your ideal weight range using four proven scientific formulas plus the healthy BMI range.
How "Ideal Weight" Is Calculated
This calculator shows results from the four most widely used ideal body weight formulas, all of which start from a base weight at 5 feet (152.4 cm) and add weight per inch of height above that:
| Formula | Men | Women |
|---|---|---|
| Devine (1974) | 50 kg + 2.3 kg/inch | 45.5 kg + 2.3 kg/inch |
| Robinson (1983) | 52 kg + 1.9 kg/inch | 49 kg + 1.7 kg/inch |
| Miller (1983) | 56.2 kg + 1.41 kg/inch | 53.1 kg + 1.36 kg/inch |
| Hamwi (1964) | 48 kg + 2.7 kg/inch | 45.5 kg + 2.2 kg/inch |
The Devine formula is the best known — it was originally created for calculating medication doses, not aesthetics, and is still used clinically today. None of these formulas were designed as appearance targets; they estimate weights associated with favourable health outcomes for a given height.
Worked Example
A man who is 175 cm (about 5'9", i.e. 9 inches over 5 feet):
- Devine: 50 + (2.3 × 9) = 70.7 kg
- Robinson: 52 + (1.9 × 9) = 69.1 kg
- Miller: 56.2 + (1.41 × 9) = 68.9 kg
- Hamwi: 48 + (2.7 × 9) = 72.3 kg
The four formulas span 68.9–72.3 kg — a reminder that "ideal" is a band, not a single number. The BMI-based healthy range for the same height is wider still: 56.7–76.3 kg.
Adjusting for Frame Size
Two people of identical height can have very different bone structure. A quick frame check: wrap your thumb and middle finger around your opposite wrist. If they overlap, you likely have a small frame (subtract ~10% from the formula results); if they just touch, medium; if they don't meet, large frame (add ~10%). Elbow breadth tables give a more formal version of the same adjustment.
Why You Shouldn't Chase a Single Number
Ideal-weight formulas know only your height and sex. They don't see muscle mass, body fat percentage, fat distribution, age or training history — all of which matter more for health than scale weight. A muscular 80 kg man at 175 cm exceeds every formula above while being objectively leaner and healthier than a sedentary 70 kg man of the same height. Use the range as a sanity check, then judge progress with better tools: our body fat calculator for composition and our BMI calculator for the standard healthy range.
Reaching Your Healthy Range
If you're outside your range, our calorie calculator gives a daily target for losing or gaining at a sustainable 0.25–0.5 kg per week. Combine it with 1.6 g+ of protein per kilogram and resistance training so the weight you lose is fat — or the weight you gain is muscle.
Frequently Asked Questions
Which ideal weight formula should I trust?
Treat the spread across all four as your answer. They differ because they were fitted to different reference data; no single one is 'correct'. If your weight is inside the band the formulas span — and your waist is under half your height — your weight is unlikely to be a health problem.
Does age change my ideal weight?
The classic formulas ignore age, but research suggests slightly higher BMIs (up to ~27) are not harmful and may be mildly protective in adults over 65, largely because reserves help during illness. Older adults should prioritise muscle retention over weight minimisation.
Why is my ideal weight different from my friend's at the same height?
Sex is the biggest factor in the formulas — male values run 3–5 kg higher at the same height. Beyond the formulas, frame size, muscle mass and fat distribution legitimately shift what a healthy weight looks like by several kilograms in either direction.
Is the ideal weight the same as the weight where I'll look best?
Not necessarily. Appearance depends mostly on body composition, not scale weight. Many people look leaner after gaining muscle at the same weight. Health-wise the formulas are a guide; aesthetics are better pursued through body fat percentage.