Ideal Weight Calculator
Find your healthy weight range for your height using four classic formulas — Devine, Robinson, Miller, and Hamwi. Results are shown as a range, not a single number.
What should you weigh for your height? Four well-known medical formulas answer that question slightly differently, which is exactly why this calculator shows all four and presents your result as a range. Enter your height and sex to see the Devine, Robinson, Miller, and Hamwi estimates side by side in kilograms and pounds.
How to use this calculator
- Enter your height in inches (for example, 70 for 5 feet 10 inches).
- Select your sex — each formula has separate versions for men and women.
- Click Calculate to see all four formula results.
- Read the highlighted range as your healthy weight zone, in both kilograms and pounds.
The formula
Each formula starts from a base weight at 5'0" and adds a fixed amount per inch above it. Devine: 50 kg + 2.3 kg/inch (men), 45.5 kg + 2.3 kg/inch (women). Robinson: 52 + 1.9/inch (men), 49 + 1.9/inch (women). Miller: 56.2 + 1.41/inch (men), 53.1 + 1.41/inch (women). Hamwi: 48 + 2.7/inch (men), 45.5 + 2.2/inch (women).
Worked example
A 5'10" (70-inch) man gets 73.0 kg from Devine, 71.0 kg from Robinson, 70.3 kg from Miller, and 75.0 kg from Hamwi — so his healthy range is about 70.3–75.0 kg, or roughly 155–165 lb.
Frequently Asked Questions
Why does this calculator show a range instead of one number?
Because the four classic formulas disagree with each other — for the same height they can differ by several kilograms. Rather than pretending one formula is the truth, this calculator shows all four estimates and highlights the range they span. A range is also more honest biologically: healthy weight depends on frame size, muscle mass, and body composition, not just height.
Which of the four formulas is the most accurate?
None of them is a gold standard — they were developed decades ago, mostly for drug-dosing purposes rather than fitness. The Devine formula (1974) is the most widely cited, Robinson and Miller are refinements of it, and Hamwi's is popular in clinical settings. For practical use, treat the middle of the range as a reasonable target and the edges as the plausible bounds.
What if my weight is above the range?
Being above the range doesn't automatically mean you're unhealthy — muscular people routinely weigh more than these formulas suggest because muscle is denser than fat. That said, for most non-athletes, sitting well above the range correlates with higher health risks. A body fat measurement or a conversation with your doctor gives a clearer picture than any height-weight formula alone.
What if my weight is below the range?
Being below the range can be perfectly fine if you're naturally slight-framed, but unintentional weight loss or difficulty maintaining weight deserves attention. If you've dropped below the range without trying, or you're actively trying to gain, talk to a healthcare professional rather than guessing — they can check for underlying causes and set a safe target.
Do these formulas work for athletes or older adults?
Not particularly well. Athletes with significant muscle mass will overshoot every formula, and older adults who have lost muscle may land 'in range' while carrying excess fat. The formulas also assume adult heights of at least 5 feet. They're a quick screening reference, not a body-composition assessment — BMI and body fat percentage fill in what these miss.