Calculate your ideal body weight based on height and sex.
Uses 4 formulas simultaneously: Broca, Devine, Robinson, and Miller. Displays the recommended average, comparison with your current weight, status (underweight/ideal/overweight), and the healthy BMI range.
Disclaimer: Results are general estimates. Consult a doctor for a comprehensive health evaluation.
Calculator information
📋 How to use this calculator
- Enter height in inches (or centimeters - the calculator converts to inches for the Broca/Devine/Robinson/Miller formulas).
- Select sex: male or female (different formulas apply).
- Optionally enter current weight for comparison.
- Review results from all four formulas (Broca, Devine, Robinson, Miller) and their average.
- Compare against the healthy weight range based on BMI 18.5-24.9.
- Check your status: under, ideal, or above the average ideal weight.
🧮 Four classic ideal body weight formulas
Height is converted to inches; H = height in inches above 5 feet (60 inches)
- Broca: IBW (kg) = (Height_cm - 100) x 0.9 (male) or 0.85 (female)
- Devine: male = 50 + 2.3 x H; female = 45.5 + 2.3 x H
- Robinson: male = 52 + 1.9 x H; female = 49 + 1.7 x H
- Miller: male = 56.2 + 1.41 x H; female = 53.1 + 1.36 x H
- Healthy BMI: 18.5-24.9 (weight range = BMI x height_m^2)
No single formula is perfect; averaging the four gives a more moderate estimate. For accurate body composition, measure body fat with bioelectrical impedance or a DEXA scan.
💡 Worked example: Female, 5'5" (165 cm)
Given:- Height: 165 cm = 64.96 inches
- Sex: female
- H (inches above 60): 64.96 - 60 = 4.96
Steps:- Broca: (165 - 100) x 0.85 = 65 x 0.85 = 55.25 kg (~121.8 lb)
- Devine: 45.5 + 2.3 x 4.96 = 45.5 + 11.41 = 56.91 kg (~125.5 lb)
- Robinson: 49 + 1.7 x 4.96 = 49 + 8.43 = 57.43 kg (~126.6 lb)
- Miller: 53.1 + 1.36 x 4.96 = 53.1 + 6.75 = 59.85 kg (~131.9 lb)
- Average: (55.25 + 56.91 + 57.43 + 59.85) / 4 = 57.36 kg (~126.5 lb)
- Healthy BMI range: 18.5 x 1.65^2 to 24.9 x 1.65^2 = 50.36 to 67.79 kg (~111-149 lb)
Result: Average ideal weight is roughly 57.4 kg (126 lb) for a 5'5" female, with a healthy range of 50-68 kg (111-149 lb) per WHO BMI.
❓ Frequently asked questions
Which formula is most accurate for ideal body weight?
No single formula works for everyone because none of them account for body composition, frame size, or muscle mass. Devine is the most common in clinical settings (used for drug dosing). Averaging all four gives a moderate estimate. For higher accuracy, combine the result with body fat percentage and waist circumference.
Is ideal body weight the same as a healthy BMI weight?
Not exactly. Ideal weight formulas return a single number, while healthy BMI (18.5-24.9) gives a range. For people of Asian descent, the WHO suggests lower thresholds (overweight at BMI 23, obesity at 27.5) because cardiometabolic risk appears at lower BMIs than in European populations.
Should athletes use the same ideal weight formulas?
Athletes typically carry more muscle mass, so weights above the classic 'ideal' or BMI cutoffs are still healthy. Bodybuilders, sprinters, and rugby players often have BMI above 25 but very low body fat (<12%). Use skinfold calipers, BIA, or a DEXA scan rather than relying on BMI.
What about ideal weight for older adults?
For adults 65 and older, the optimal BMI range shifts slightly higher: about 23-28. Being underweight raises the risk of sarcopenia, fractures, and mortality. Studies show older adults with BMI 25-29 have lower mortality than those under 23. Focus on muscle strength and protein intake rather than driving weight down to an 'ideal' number.
Is ideal weight different for men and women?
Yes. All the classic formulas (Devine, Robinson, Miller) give roughly 4-5 kg (9-11 lb) lower ideal weights for women at the same height. Women on average have smaller frames and less muscle mass. Broca uses correction factors (0.9 male vs 0.85 female) for the same reason. None of these formulas adjust for ethnicity or body shape.
📚 Sources & references
Last updated: May 11, 2026