Ideal Weight Calculator
Estimate your ideal body weight using four established medical formulas. A useful reference range based on your height and sex.
What is ideal body weight?
Ideal body weight (IBW) is an estimate of a healthy weight for a person of a given height and sex. The concept was originally developed in medicine to help calculate medication dosages and assess nutritional status, and it remains a useful reference point. This calculator shows results from four well-established formulas — Devine, Robinson, Miller and Hamwi — along with their average, because no single formula is universally agreed to be best.
How the formulas differ
Each formula starts from a base weight at a height of five feet and adds a set amount for every inch above that, with different values for men and women. The Devine formula is the most widely used, especially in clinical settings for drug dosing. The Robinson, Miller and Hamwi formulas were developed to refine these estimates. They produce slightly different numbers, which is why seeing them together, and their average, gives a more balanced picture than relying on one.
What ideal weight does and doesn't tell you
Ideal body weight is a height-based estimate and a useful starting reference, but it has real limitations. It does not account for your body composition — muscle weighs more than fat, so a muscular athlete may sit well above their calculated ideal weight while being very healthy. It also does not consider frame size, age or individual health. Treat the result as one data point among several, alongside measures like BMI, body fat percentage and waist circumference.
Using ideal weight sensibly
Rather than chasing an exact ideal weight number, it is more useful to aim for a healthy range and focus on overall health markers: how you feel, your fitness, your blood pressure and blood sugar, and your body composition. If your weight is significantly above or below the estimated ideal range and you are concerned, a doctor or dietitian can help you interpret what it means for you specifically and set realistic, healthy goals.
Frequently Asked Questions
Ideal body weight formulas use your height and sex. They start from a base weight at five feet tall and add a fixed amount per inch above that. This calculator uses four established formulas — Devine, Robinson, Miller and Hamwi — and shows their average for a balanced estimate.
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Sources & References
- 1.Devine BJ.. Gentamicin therapy (origin of the Devine ideal body weight formula).
- 2.Robinson JD, et al.. Determination of ideal body weight for drug dosage calculations.
- 3.Pai MP, Paloucek FP.. The origin of the ideal body weight equations.
LifeCheckIQ content is based on peer-reviewed research, recognised clinical guidelines, and authoritative medical sources, and is reviewed by Deborah Adotso, General Nurse, for clinical accuracy.
Medical Disclaimer: This tool is for informational and educational purposes only. Results are not a medical diagnosis. Always consult a qualified healthcare professional for medical advice, diagnosis, or treatment. In an emergency, call your local emergency number or visit the nearest hospital immediately.