The 5 Ideal Weight Formulas
No single formula defines the "perfect" ideal weight — each was developed for a different purpose. Comparing all five gives you a practical target range rather than a single arbitrary number.
Hamwi Formula (1964)
Originally developed for clinical weight assessment: Men: 106 lbs for 5 feet + 6 lbs per inch above 5'. Women: 100 lbs for 5 feet + 5 lbs per inch above 5'. Simple and widely cited, but gives a single number rather than a range and doesn't account for frame size or body composition.
Devine Formula (1974)
Created for pharmacological dosing calculations (determining drug doses based on body weight): Men: IBW = 50 kg + 2.3 kg per inch over 5'. Women: IBW = 45.5 kg + 2.3 kg per inch over 5'. Still widely used in ICU and clinical settings. Similar to Hamwi but in metric units.
Robinson Formula (1983)
A modification of the Devine formula: Men: IBW = 52 kg + 1.9 kg per inch over 5'. Women: IBW = 49 kg + 1.7 kg per inch over 5'. Tends to give slightly higher estimates than Devine for taller individuals.
Miller Formula (1983)
Another Devine modification: Men: IBW = 56.2 kg + 1.41 kg per inch over 5'. Women: IBW = 53.1 kg + 1.36 kg per inch over 5'. Gives the highest estimates of the four clinical formulas, particularly for taller people.
Healthy BMI Range (Most Recommended)
The World Health Organization defines a healthy BMI as 18.5–24.9. The corresponding weight range at your height gives the most evidence-based target. For most adults, this is the most practical and health-relevant target. Note that it produces a range (not a single number) which is more realistic and accounts for natural variation in body composition.
Why the 5 Formulas Give Different Results
The four clinical formulas (Hamwi, Devine, Robinson, Miller) were never designed to define health goals — they were created to calculate medical drug dosing, where lean body mass determines how drugs distribute in tissues. They're widely cited as "ideal weight" references despite having no direct research support for that purpose. The Healthy BMI Range method is the most appropriate for personal health goals because it's derived from epidemiological health outcomes data (where weight-related disease risk is actually lowest).
The spread between formulas at any given height can be 10–20 lbs. A 5'8" man gets results from 154 lbs (Devine) to 167 lbs (Miller) — a 13-lb range. This spread illustrates that "ideal weight" is genuinely a range, not a number, and that picking any single formula's result as a goal is somewhat arbitrary.
Ideal Weight Ranges by Height: A Quick Reference
The WHO Healthy BMI method gives these weight ranges for common adult heights (BMI 18.5–24.9):
| Height | Healthy Weight Range (Men) | Healthy Weight Range (Women) |
|---|---|---|
| 5'2" (157 cm) | 102–136 lbs | 101–135 lbs |
| 5'4" (163 cm) | 110–147 lbs | 108–144 lbs |
| 5'6" (168 cm) | 118–154 lbs | 115–154 lbs |
| 5'8" (173 cm) | 125–163 lbs | 122–163 lbs |
| 5'10" (178 cm) | 132–174 lbs | 129–173 lbs |
| 6'0" (183 cm) | 140–183 lbs | 136–182 lbs |
Should You Try to Hit "Ideal" Weight?
Research consistently shows that losing 5–10% of body weight produces significant health improvements even when you remain in the "overweight" BMI range. You don't need to reach your ideal weight to see reduced blood pressure, improved insulin sensitivity, and lower cardiovascular risk. Setting "ideal weight" as an all-or-nothing goal creates unnecessary psychological burden — a better frame is "healthier weight direction" rather than a fixed target number.
For people with a healthy BMI who want to change their physique, shifting focus from scale weight to body composition (reducing fat while building muscle) often produces better aesthetic and health results than chasing a specific number. Two people at the same weight can look and feel very different depending on their muscle-to-fat ratio.
Your ideal weight range is a starting point. Use our BMI Calculator to see your current status — or calculate how many calories you'd need to reach your target with our Calorie Calculator.