About Ideal Weight Calculator
The Ideal Weight Calculator estimates your optimal body weight using four established medical formulas developed between 1871 and 1983: Devine, Robinson, Miller, and Hamwi. Each formula takes a slightly different approach to calculating ideal weight based on height and gender, typically starting with a base weight for five feet of height and adding incremental weight for each additional inch. The Devine formula was originally developed for medication dosing calculations, the Robinson formula was derived from life insurance data, the Miller formula updated the concept for modern populations, and the Hamwi formula offered a simple clinical shortcut. Since these formulas can produce varying results, the calculator presents all four side by side for comparison. It also computes your healthy weight range based on the BMI standard of 18.5 to 24.9, giving you a broader perspective on where a healthy weight might fall for your specific height. Use the results as general reference points rather than absolute targets, as individual healthy weights vary based on muscle mass, bone density, and body composition.
When to Use This Calculator
Use this calculator if you're curious about where your weight falls relative to medical standards. It's helpful when discussing weight goals with your healthcare provider, as different doctors may reference different formulas. Some medication dosages are still calculated using the Devine formula, so knowing your ideal weight from that method can be relevant for medical purposes. Fitness enthusiasts use it as one of several reference points when setting goal weights. For example, a 175 cm man might see Devine says 72.5 kg, Robinson says 71.3 kg, Miller says 72.8 kg, and Hamwi says 74.5 kg. All are close, giving him confidence that aiming for about 72 to 74 kg is reasonable. However, remember that these formulas were developed decades ago and don't account for muscle mass, so a muscular person might healthily exceed all four numbers.
How to Interpret Your Results
The results show four formula results plus the BMI-based healthy weight range. For our 165 cm woman, the four formulas give 56.3 to 59.4 kg, a narrow range. The BMI healthy range of 50.4 to 67.8 kg gives a wider perspective. If she currently weighs 72 kg, she's above all four formula estimates and slightly above the healthy BMI range. This tells her that losing some weight could be beneficial, but she doesn't need to hit exactly 56.3 kg. Any weight between 50.4 and 67.8 kg falls in the healthy BMI zone. The differences between formulas exist because they were developed for different purposes. Devine was for medication dosing, so it's more conservative. Robinson used healthier insurance policyholders. Miller adjusted upward for modern, taller populations. Hamwi was a quick clinical estimate. None of these are "right" or "wrong," which is why seeing all four gives you a better sense of the range rather than a single target.
How to Use This Calculator
Select your gender and enter your height in centimeters. Let's use an example. A 35-year-old woman who is 165 cm tall (about 5 feet 5 inches) would select "Female" and enter 165. After clicking calculate, the results show her ideal weight from four different formulas. The Devine formula gives her about 56.3 kg, Robinson gives her about 57.6 kg, Miller gives her about 59.4 kg, and Hamwi gives her about 56.7 kg. The calculator also shows her healthy BMI range, which for 165 cm is approximately 50.4 kg to 67.8 kg. Notice how the four formula results cluster around 57 to 59 kg, while the healthy BMI range gives a wider spread. This shows the range of healthy possibilities. Try adjusting the height to see how the ideal weight changes with every centimeter.