βοΈ Ideal Weight Calculator
Four clinical formulas, one honest range.
For informational purposes only, not medical advice. Consult a healthcare professional.
Four Formulas, One Range
Doctors have used ideal body weight formulas for decades to dose medications and set targets. This calculator runs all four major ones: Devine (the original, from drug dosing), Robinson (a refinement), Miller (a further refinement), and Hamwi (popular in clinical practice). For a 5-foot-8 man they give roughly 164, 157, 156, and 165 pounds. The spread is the point: there is no single ideal number, only a healthy range, and the calculator shows you the full spread so you can see where the formulas agree.
Each formula starts from a base weight at 5 feet and adds a fixed amount per inch above that. Devine: men 50 kg + 2.3 per inch over 5 feet, women 45.5 + 2.3. Robinson: men 52 + 1.9, women 49 + 1.7. Miller: men 56.2 + 1.41, women 53.1 + 1.36. Hamwi: men 106 lbs + 6 per inch, women 100 + 5. They were designed for medication dosing, not aesthetics, which is exactly why they make good neutral targets.
What the Formulas Miss
None of them know your frame size, muscle mass, or body composition. A lifter with an FFMI of 23 will weigh well above every formula and be perfectly healthy; a sedentary person at the formula weight with high body fat may not be. Use the range as a starting reference, then refine with body fat percentage, waist measurements, and how you actually feel and perform. Pair this with our BMI and body fat calculators for the full picture.
Setting a Realistic Goal
If you are above the range, aim first for the top of it, not the middle: a 5-foot-8 man at 200 pounds targeting 165 has a 35-pound journey, and the first 10 pounds deliver most of the health benefit. Studies show 5 to 10 percent weight loss meaningfully improves blood pressure, blood sugar, and joint load. Reassess at each milestone rather than fixating on a single number from day one. For informational purposes only, not medical advice. Consult a healthcare professional.
Frequently Asked Questions
Which ideal weight formula is most accurate?
None is perfect; they were designed for drug dosing. Robinson and Miller are refinements of Devine that fit population data better. The honest approach is the range across all four, which this calculator shows.
Why do the four formulas disagree?
Each uses a different base weight and per-inch increment, fitted to different datasets decades ago. The 5 to 10 pound spread between them is normal and is itself useful information: it shows the uncertainty in any single number.
Should athletes use ideal weight formulas?
As a rough reference only. Muscular people routinely and healthily exceed every formula. Body fat percentage and FFMI are better guides for trained individuals.
What if I am below the ideal range?
Being underweight carries its own risks: nutrient deficiency, low bone density, and weakened immunity. If you are below the range unintentionally, see a doctor to rule out underlying causes.
How fast should I work toward my ideal weight?
One to two pounds per week is the standard safe rate. Faster loss sacrifices muscle. Aim first for the top of the range, reassess, then continue if appropriate.