Ideal Weight Calculator - Free Estimate
Calculate your ideal body weight using multiple scientific formulas. Plus, see body composition-based targets that account for your muscle mass—not just your height.
The Problem with Ideal Weight Formulas
Ideal weight formulas were developed decades ago and have significant limitations. A 2015 review in Nutrition Today concluded that BMI, which like ideal weight formulas uses only height and weight, is "a rather poor indicator of percent of body fat."
Ignores Body Composition
These formulas can't distinguish between muscle and fat. A muscular 180 lb person is very different from a sedentary 180 lb person.
One-Size-Fits-All
Formulas don't account for frame size, bone density, or individual variation. A large-framed person has different needs than small-framed.
Outdated Research
Most formulas are 40-60 years old and were developed on limited populations that may not represent modern demographics.
Originally for Drug Dosing
The Devine formula was created for medication dosing, not fitness goals. It was never intended as a health metric.
Ideal Weight Calculator
Your Measurements
Optional: Body Composition Data
Add your current weight and body fat % for personalized targets based on your lean mass.
Don't know your body fat? Get AI analysis
Weight Is Just One Number
Body composition tells the full story
Your ideal weight depends on how much muscle you carry, not just your height. PhysiqueAI estimates your body composition from a photo so you can set targets around it.
- Body fat percentage estimate
- Lean body mass estimate
- Track progress over time
Free account • Full results with Premium
Ideal Weight Formulas Compared
| Formula | Male | Female | Notes |
|---|---|---|---|
| Devine (1974) | 50 + 2.3 kg per inch over 5'0" | 45.5 + 2.3 kg per inch over 5'0" | Most widely used, originally for drug dosing |
| Robinson (1983) | 52 + 1.9 kg per inch over 5'0" | 49 + 1.7 kg per inch over 5'0" | Modification of Devine, lower increments |
| Miller (1983) | 56.2 + 1.41 kg per inch over 5'0" | 53.1 + 1.36 kg per inch over 5'0" | Higher base, lower increments per inch |
| Hamwi (1964) | 48 + 2.7 kg per inch over 5'0" | 45.5 + 2.2 kg per inch over 5'0" | Oldest formula, higher increments |
All formulas use 5'0" (60 inches) as the baseline height. The base weight is adjusted by a per-inch factor for each inch above 60 inches. These formulas assume average body composition and frame size.
Body Composition vs Weight Formulas
Weight Formulas Tell You:
- A generic number based on height only
- The same target regardless of muscle mass
- Nothing about health or body composition
Body Fat % Tells You:
- Your actual fat vs muscle ratio
- A personalized target based on YOUR body
- Whether you're losing fat or muscle
- Real health indicators, not just weight
What the Research Says
Limitations of Weight-Based Metrics
A 2015 review in Nutrition Today and related research highlight the limits of height-and-weight metrics:
- Standard BMI cutoffs miss about half of people with excess body fat (Int J Obes, 2010 meta-analysis)
- "Normal" weight individuals can have unhealthy body fat levels
- Weight alone doesn't tell you how much of it is fat
Body Composition Matters More
Research suggests body composition should guide weight goals:
- BMI predicts body fat with wide individual variability (J Clin Endocrinol Metab, 2025)
- Higher relative muscle mass is linked to lower insulin resistance (J Clin Endocrinol Metab, 2011)
- "Ideal" weight varies based on individual body composition
Frequently Asked Questions
Which ideal weight formula is most accurate?
No formula is universally accurate. They all assume average body composition. For fitness goals, using body fat percentage targets is more meaningful than any formula.
Why is my ideal weight different from what I expected?
Formulas give statistical averages, not personalized recommendations. If you have more muscle than average, your healthy weight will be higher than these estimates suggest.
Should I trust BMI or ideal weight formulas?
Both are screening tools with significant limitations. Neither accounts for muscle mass. Body fat percentage is a much better indicator of health and fitness.
I'm muscular but these formulas say I'm overweight. What should I do?
Ignore weight-based formulas. Focus on body fat percentage instead. A muscular person at a 'high' weight but 12% body fat is healthier than someone at their 'ideal' weight with 30% body fat.
How do I calculate my ideal weight based on body fat?
Find your lean body mass (weight x (1 - body fat%)). Then divide by (1 - target body fat%). This preserves your muscle while achieving your desired body composition.
What's a healthy body fat percentage to target?
For men: 10-20% is healthy, with athletes at 6-13%. For women: 18-28% is healthy, with athletes at 14-20%. Choose based on your goals and lifestyle sustainability.
Focus on Body Composition, Not Just Weight
Estimate your body fat to set meaningful goals. Your ideal weight should be based on your unique body, not a generic formula.
Free account • Full results with Premium