Ideal Body Weight Calculator
This calculator provides estimates for educational purposes only and is not medical advice. Results may vary based on individual factors. Consult a healthcare provider before making changes to your diet or exercise routine.
What is Ideal Body Weight?
Ideal Body Weight (IBW) is an estimated weight range considered healthiest for a person based on their height and gender. Unlike BMI, which simply categorizes you into weight classes, IBW gives you a specific target weight to aim for. It helps set realistic goals whether you are trying to lose weight or maintain a healthy physique.
Our calculator shows the four most widely used published formulas - Devine, Robinson, Miller, and Hamwi - side by side, together with the WHO healthy weight range for your height, so you get a realistic window instead of a single number.
How the formulas work
Several scientific formulas have been developed over the decades to estimate ideal weight. The most commonly used are:
- Devine formula (1974): The most widely used in clinical settings. Originally developed for drug dosage calculations.
- Robinson formula (1983): A revision of Devine that tends to give slightly lower estimates.
- Miller formula (1983): Starts from a higher base but climbs more slowly with height, so it gives the highest estimates for shorter people.
- Hamwi formula (1964): The oldest of the four, created as a quick bedside estimate for clinicians.
All formulas use height as the primary input and adjust by gender. Results can vary by 5-15 lbs between methods - this is normal. They are population estimates that ignore muscle mass and frame size, so treat the range as a realistic target window rather than a single number.
What to do with your result
Once you know your ideal weight range, the next step is figuring out how to get there (or stay there). Check your BMI to see where you currently stand, then use our Daily Calorie Intake Calculator to find out how many calories you need each day. If you have weight to lose, the Weight Loss Calculator can show you a realistic timeline to reach your ideal weight.
Frequently asked questions
What is ideal body weight?
Ideal body weight (IBW) is an estimated weight range considered healthiest for a person based on their height and gender. It is not a single number but a range that accounts for individual variation.
How is ideal body weight calculated?
Several scientific formulas calculate IBW, including the Devine, Robinson, Miller, and Hamwi formulas. Each uses height and gender as primary inputs, and results may vary slightly between methods.
Is ideal body weight the same as BMI?
No. BMI is a ratio of weight to height that categorizes you into weight classes. Ideal body weight is a specific weight target. A person can have a normal BMI but be above or below their ideal weight for their frame.
How accurate is ideal body weight?
IBW formulas provide a reasonable target for most people, but they do not account for muscle mass, bone density, or body composition. Athletes or people with high muscle mass may weigh more than their calculated IBW while being perfectly healthy.
How much should I weigh for my height?
Your ideal weight depends on your height and gender. As a rough guide, the four formulas put a 5'4" woman's ideal weight at approximately 120-129 lbs and a 5'10" man's at approximately 155-165 lbs. Use our calculator for a personalized range.
Formulas and scientific references Devine (1974), Robinson (1983), Miller (1983) and Hamwi (1964) ideal body weight formulas, shown next to the WHO healthy-weight band (BMI 18.5-24.9).
Sources
- Devine BJ. Gentamicin therapy. Drug Intelligence and Clinical Pharmacy, 1974;8:650-655
- Robinson JD, et al. Determination of ideal body weight for drug dosage calculations. American Journal of Hospital Pharmacy, 1983;40(6):1016-1019
- Miller DR, et al. Determining ideal body weight (and mass). (Letter.) American Journal of Hospital Pharmacy, 1983;40(10):1622, 1625
- Hamwi GJ. Diabetes Mellitus: Diagnosis and Treatment. American Diabetes Association, 1964
- World Health Organization BMI classification for adults (underweight below 18.5, healthy weight 18.5-24.9, overweight 25.0-29.9, obesity from 30.0). World Health Organization, Nutrition Landscape Information System
This calculator gives a general educational estimate, not medical or individualized nutrition advice. Prediction equations are wrong by more than 10% in roughly 1 in 3 people.