Ideal Weight Calculator
Estimate your ideal body weight using the Devine formula, still widely cited by clinicians today.
What is "ideal weight"?
Ideal body weight (IBW) is an estimate historically used in clinical settings — most notably for calculating medication dosages — to approximate a healthy weight based on height and sex. It's not a personalized fitness target and doesn't account for muscle mass, frame size, or body composition, but it remains a useful clinical reference point and a rough benchmark for general population comparisons.
The Devine formula
This calculator uses the Devine formula, originally published in 1974 and still commonly used by clinicians and pharmacists today for dosing calculations. For men, ideal weight (kg) = 50 + 2.3 × (height in inches − 60). For women, ideal weight (kg) = 45.5 + 2.3 × (height in inches − 60). The formula is anchored to 5 feet (60 inches), adding 2.3 kg for each inch of height above that baseline. For people at or under 5 feet, the base value (50 kg for men, 45.5 kg for women) is used.
A range, not a single number
Because no single formula perfectly captures a healthy weight for every body type, this calculator also shows a healthy weight range based on a BMI of 18.5-24.9 for your height — the same range used by our BMI calculator. Use both figures as general reference points rather than a strict target. This is an estimate only and not medical advice.
Frequently Asked Questions
What formula does this ideal weight calculator use?
This calculator uses the Devine formula, first published in 1974, which is still commonly used by clinicians and pharmacists today, especially for calculating medication dosages based on body weight.
Is "ideal weight" the same as my healthy weight goal?
Not necessarily. Ideal body weight formulas like Devine were designed as clinical reference points, not personalized fitness targets. They don't account for muscle mass, bone density, or frame size, so the healthy weight range shown alongside your result is often a more practical target.
Why do men and women have different ideal weight formulas?
The Devine formula uses a lower base weight for women (45.5 kg vs. 50 kg for men) to reflect average differences in body composition and frame size between sexes at the same height.
What happens if I'm shorter than 5 feet tall?
The Devine formula is anchored at 60 inches (5 feet). For heights at or below that mark, this calculator shows the base value — 50 kg for men or 45.5 kg for women — since the formula wasn't designed to subtract weight for height below its baseline.
Why does my ideal weight differ from what I actually weigh at a healthy BMI?
Ideal weight formulas and BMI-based ranges use different methodologies and were developed for different purposes, so they won't always agree exactly. That's why this calculator shows both figures — use the range as the more flexible, realistic target.
Does this calculator account for muscle mass or body frame size?
No. Like most ideal weight formulas, Devine's equation only uses height and sex. Muscular individuals or those with larger bone structure may naturally weigh more than the formula suggests without being unhealthy.
Are there other ideal weight formulas besides Devine?
Yes — the Robinson, Miller, and Hamwi formulas are other commonly cited ideal weight equations, each with slightly different coefficients. They generally produce similar results, with Devine remaining the most widely used in clinical practice.
Is this ideal weight calculator medical advice?
No. This tool provides a general estimate for informational purposes only and is not a substitute for advice from a doctor, dietitian, or other qualified healthcare provider.