Quick Answer
Pick your gender, frame size and height in the calculator below to get a medically grounded ideal weight target.
The tool averages the Devine (1974) and Hamwi (1964) formulas, then applies a ±10% adjustment for your skeletal frame.
It also returns your healthy BMI range (18.5 to 24.9) so you have a target band, not just a single number.
What is ideal body weight?
Ideal Body Weight (IBW) is a clinical estimate of a healthy weight range based on height, gender and bone structure. The formulas were originally built for safe drug dosing, which is why they are still trusted by pharmacists and physicians today.
Unlike BMI, which is purely statistical, IBW gives you a single goal weight grounded in decades of medical practice. Pair the two and you get both a target and a range.
Why frame size matters
Your skeleton has weight. Two people of the same height can have meaningfully different ideal weights if one has wider bones. The standard adjustment is ±10%.
- Small frame: subtract 10% from the formula result.
- Medium frame: use the formula result as-is.
- Large frame: add 10% to the formula result.
Ideal Weight Calculator
Devine and Hamwi averaged, adjusted for body frame.
Estimate your medically ideal weight using the two most cited clinical formulas, adjusted for your frame.
The four ideal weight formulas
Several formulas have been published over the years. Each is calibrated slightly differently. The calculator uses the Devine and Hamwi average for a balanced result.
| Formula | Year | Tendency | Best for |
|---|---|---|---|
| Devine | 1974 | Standard | Medical dosing, the clinical default |
| Hamwi | 1964 | Heavier | Quick rule-of-thumb estimate |
| Robinson | 1983 | Lighter | Refined modern average |
| Miller | 1983 | Lean | Conservative target |
How to measure your frame size
Wrap a tape measure around the smallest part of your wrist, just below the wrist bone.
| Wrist circumference | Men | Women |
|---|---|---|
| Small frame | under 7" | under 6" |
| Medium frame | 7" to 7.5" | 6" to 6.5" |
| Large frame | over 7.5" | over 6.5" |
Common ideal weights by height
Quick reference for medium-frame adults using the Devine and Hamwi average.
| Height | Men (kg) | Women (kg) |
|---|---|---|
| 5'2" (157 cm) | ~55 kg | ~50 kg |
| 5'6" (168 cm) | ~64 kg | ~59 kg |
| 5'10" (178 cm) | ~73 kg | ~68 kg |
| 6'2" (188 cm) | ~82 kg | ~77 kg |
Who should use this tool
This calculator is designed for healthy adults aged 18 and over who are setting long-term weight goals. It works for fat loss planning, weight maintenance and general health screening.
It is not appropriate for children, pregnant women or anyone managing a clinical condition that affects body composition.
Limitations for athletes
IBW formulas do not measure muscle. Muscle is denser than fat, so trained lifters and athletes routinely sit above their "ideal" weight while still being lean and healthy.
If you carry meaningful muscle, treat the result as a minimum baseline and use body fat percentage as your real composition metric.
Methodology
The calculator averages two trusted formulas, then applies your frame adjustment.
- Devine (Men): 50 kg + 2.3 kg per inch over 5 ft.
- Devine (Women): 45.5 kg + 2.3 kg per inch over 5 ft.
- Hamwi (Men): 48 kg + 2.7 kg per inch over 5 ft.
- Hamwi (Women): 45.5 kg + 2.2 kg per inch over 5 ft.
- Frame adjustment: small −10%, medium ±0%, large +10%.
- Healthy range: BMI 18.5 to 24.9 applied to your height in metres.
Frequently asked questions
What should my ideal weight actually be?
There is no single perfect number. The calculator gives a medically accepted target, but a healthy weight is really a range that spans small, medium and large frames.
Which formula is most accurate?
The Devine formula (1974) is the most widely accepted clinical standard. Hamwi is the most common quick estimate. I average the two so you get a balanced midpoint.
Does this work in kilograms?
Yes. Toggle between metric (cm/kg) and imperial (in/lbs) at the top of the calculator. The medical formulas are converted automatically.
Why are men's and women's targets different?
Men typically carry more muscle mass and denser bone structure. The formulas were calibrated separately to reflect that biology.
How do I measure my frame size?
Use a tape around the smallest part of your wrist. The table above shows the small/medium/large thresholds for men and women.
Is there an ideal weight for my age?
The classic formulas depend on height only. Older adults often benefit from carrying slightly more weight to support bone density, but the medical target stays the same.
Is this tool suitable for kids?
No. IBW formulas are built for fully developed adult bodies. For children and teenagers, use the CDC growth charts with a paediatrician.
Why do athletes weigh more than their ideal?
Muscle is denser than fat. A muscular athlete can sit 10 to 20% above their IBW and still be healthier than someone at the "perfect" number with low muscle mass.
What if I am far from my ideal range?
These are long-term targets. Even losing or gaining 5 to 10% of your bodyweight produces measurable improvements in blood pressure, blood sugar and cholesterol.
Is my data safe?
Yes. The calculation runs entirely in your browser. Nothing is stored or sent to a server.
Related calculators
- BMI Calculator, check your weight against WHO classifications.
- Body Fat Calculator, a richer composition reading than weight alone.
- Calorie Calculator, set a sensible deficit or surplus to reach your range.
Medical disclaimer
This calculator and article are for general educational and wellness purposes only. They are not a substitute for professional medical advice, diagnosis or treatment. Results are estimates based on population formulas and do not account for every individual factor.
If you are pregnant or breastfeeding, under 18, over 65, an athlete, recovering from illness or surgery, or living with a chronic condition (diabetes, heart, kidney, thyroid, eating disorder), speak to a qualified healthcare professional before changing your diet, exercise or hydration habits based on these numbers.
See the full site-wide Disclaimer & Notice for the complete terms that apply to every calculator and tool on dmbio.
