Find your ideal weight in seconds
Enter your height and gender to see your ideal weight from four medical formulas, plus the healthy BMI range.
Ideal weight formulas compared
Each formula starts from a base weight at 5 feet tall, then adds a fixed amount per inch above that.
| Formula | Base at 5ft | Per inch over 5ft | Notes |
|---|---|---|---|
| Devine | 50 kg (M) / 45.5 kg (F) | +2.3 kg (M) / +2.3 kg (F) | The most widely used clinically, originally for drug dosing. |
| Robinson | 52 kg (M) / 49 kg (F) | +1.9 kg (M) / +1.7 kg (F) | A 1983 refinement of Devine with adjusted increments. |
| Miller | 56.2 kg (M) / 53.1 kg (F) | +1.41 kg (M) / +1.36 kg (F) | Tends to give the lowest estimate of the four formulas. |
| Hamwi | 48.0 kg (M) / 45.5 kg (F) | +2.7 kg (M) / +2.2 kg (F) | A 1964 formula still common in clinical nutrition. |
Want your own number for each formula? Use the ideal weight calculator above.
About ideal weight formulas
"Ideal body weight" formulas were originally developed decades ago, mostly to help clinicians calculate medication dosages quickly from a patient's height. Devine (1974) is the most widely used; Robinson, Miller, and Hamwi followed with their own adjustments.
Each formula starts with a base weight at 5 feet tall, then adds a fixed amount for every inch above that — the exact base and per-inch amount differ slightly between formulas, which is why they don't all agree on the same height.
None of these formulas account for muscle mass, bone density, or body frame, so they work best as a general reference range rather than a strict target. This calculator shows all four side by side, plus the healthy weight range from BMI, so you can see the full spread rather than relying on a single number.
Ideal weight questions
What these formulas mean and how to use them.
What is ideal body weight?
Ideal body weight (IBW) is an estimated healthy weight for a given height, originally developed to help calculate medication dosages. It's a reference point, not a strict target — actual healthy weight varies by build, muscle mass, and age.
How is ideal weight calculated?
Several formulas estimate ideal weight from height and gender: Devine, Robinson, Miller, and Hamwi. Each uses a base weight at 5 feet tall, then adds a fixed amount per inch above that. This calculator shows all four plus the healthy BMI weight range.
Which ideal weight formula is most accurate?
None is definitively "most accurate" — they were developed for different purposes (mainly drug dosing) and can differ by several pounds for the same height. Most people find it more useful to look at the range across all formulas rather than a single number.
Does ideal weight depend on frame size or muscle mass?
The classic formulas only use height and gender, so they don't account for frame size, muscle mass, or body composition. Someone with a muscular or large-framed build will often weigh more than these formulas suggest while still being perfectly healthy.
What's the difference between ideal weight and BMI?
BMI gives a healthy weight range based on height alone, using the same 18.5–24.9 range for everyone. Ideal weight formulas instead estimate a single target weight per height and gender. Both are screening tools, not diagnoses.
Can I be healthy outside my ideal weight range?
Yes. These formulas are decades-old estimates that don't account for individual differences like muscle mass, bone density, or overall fitness. Use them as a general reference, and talk to a healthcare provider about what's healthy for your specific body.
Why do the formulas give different numbers?
Each formula was developed independently, using different populations and assumptions. Devine is the most widely used clinically, Miller tends to give the lowest estimates, and Hamwi tends to run higher — seeing them side by side shows the real spread in these estimates.