Ideal Weight Calculator
Estimate your ideal body weight using four widely used clinical formulas. Enter your height and sex to see results across all four methods.
These are statistical estimates based on height. Individual healthy weight varies based on muscle mass, bone density, and other factors.
What is ideal body weight?
Ideal body weight (IBW) is a statistical estimate of the weight associated with the lowest mortality risk for a given height and sex. These formulas were developed in clinical settings — primarily to estimate drug dosages — not as personal fitness targets. They do not account for body composition, muscle mass, or bone density.
The four formulas this calculator uses are among the most widely cited in medical literature. They were all derived from population data and produce similar but slightly different results:
- Devine (1974) — originally developed for creatinine clearance dosing, now the most widely used
- Robinson (1983) — slightly lower estimates than Devine, developed for drug dosage accuracy
- Miller (1983) — produces the highest IBW estimates among the four
- Hamwi (1964) — one of the oldest formulas, commonly cited in dietetics
How are ideal weight formulas calculated?
All four formulas share the same structure: a base weight for a 5-foot (152.4 cm) person, plus a fixed amount per inch above 5 feet. For example, the Devine formula gives 50 kg for a 5'0" male, and adds 2.3 kg for each additional inch of height.
This calculator averages the four results to provide a single reference figure. The average reduces the variance from any one formula and gives a more balanced estimate.
Frequently asked questions
Is my ideal weight the same as a healthy BMI weight?
Not exactly. BMI targets a range (18.5–24.9), while IBW formulas produce a single point estimate. The IBW results typically fall within the healthy BMI range but may not perfectly match the BMI midpoint.
Should I use this as a weight loss target?
IBW formulas are rough estimates, not personalised targets. Athletes and muscular individuals often weigh significantly more than their IBW while remaining in excellent health. Use these numbers as a general reference, not a goal.
What if my current weight is below the ideal weight range?
Being significantly below your IBW may indicate low muscle mass or nutritional concerns. Speak with a healthcare provider if you are concerned about being underweight.
Do these formulas work for children?
No. All four formulas are validated for adults aged 18 and over. Paediatric weight assessment uses age- and sex-adjusted growth charts instead.
