Ideal Weight Calculator
Estimate your ideal body weight from your height and sex using several established formulas, plus the healthy weight range for your height.
| Formula | Ideal weight |
|---|---|
| Devine | 161 lb |
| Robinson | 157 lb |
| Miller | 155 lb |
| Healthy BMI range | 129–174 lb |
"Ideal weight" formulas are rough guides based only on height and sex; they don't account for build, muscle, or frame size. Not medical advice.
How to use this calculator
Select your biological sex and enter your height in feet and inches. The calculator returns the result from each classic ideal weight formula (Devine, Robinson, Miller, Hamwi), an averaged estimate, and the healthy weight range for your height based on a BMI of 18.5–24.9.
Where do ideal weight formulas come from?
The concept of an "ideal body weight" grew out of clinical medicine, not fitness culture. The earliest widely-used formula was proposed by Benjamin Devine in 1974 as a shorthand for estimating lean body mass when dosing medications — a practical tool for pharmacists, not a definition of the best weight to strive for. Subsequent researchers (Robinson in 1983, Miller in 1983, Hamwi somewhat earlier) proposed their own versions with slightly different starting points and per-inch increments, based on different reference populations.
None of these formulas was validated as a health or longevity target. They are convenient approximations based on height and sex — fast to calculate and useful as rough benchmarks, but not precise predictions of what any individual should weigh for optimal health.
The four classic formulas
- Devine: Men: 50 kg + 2.3 kg per inch over 5 ft. Women: 45.5 kg + 2.3 kg per inch over 5 ft.
- Robinson: Men: 52 kg + 1.9 kg per inch over 5 ft. Women: 49 kg + 1.7 kg per inch over 5 ft.
- Miller: Men: 56.2 kg + 1.41 kg per inch over 5 ft. Women: 53.1 kg + 1.36 kg per inch over 5 ft.
- Hamwi: Men: 48 kg + 2.7 kg per inch over 5 ft. Women: 45.4 kg + 2.2 kg per inch over 5 ft.
All four formulas use the same basic structure; they differ only in the base weight and per-inch increment. The spread between the highest and lowest result for a given height is typically 10–15 lb.
The healthy BMI range as an alternative guide
Rather than a single number, a BMI of 18.5–24.9 defines a range of weights associated with lower health risk at the population level. This range is derived from decades of epidemiological data linking BMI to outcomes like cardiovascular disease, type 2 diabetes, and all-cause mortality. For most adults it gives a more practical and evidence-grounded target than any single ideal-weight formula.
Worked example — step by step
For a man who is 5 feet 10 inches (70 inches, or 10 inches over 5 feet):
- Devine: 50 + (10 × 2.3) = 73 kg ≈ 161 lb
- Robinson: 52 + (10 × 1.9) = 71 kg ≈ 157 lb
- Miller: 56.2 + (10 × 1.41) = 70.3 kg ≈ 155 lb
- Hamwi: 48 + (10 × 2.7) = 75 kg ≈ 165 lb
The average of the four is roughly 160 lb. The healthy BMI range for the same person spans approximately 129–173 lb — a wider and arguably more realistic band.
How to interpret your result
Think of the ideal weight numbers as directional guides, not targets to hit precisely. If your current weight is within or near the healthy BMI range and your other health indicators are good, chasing a lower formula number is unlikely to add health benefit. If you are substantially above the range, modest loss toward the upper end — even 5–10% of body weight — is associated with meaningful metabolic improvements.
Common mistakes to avoid
- Treating a single formula result as a precise goal. A range is more honest than a single number; use the BMI band alongside the formula estimates.
- Ignoring body composition. A lean, muscular person and a sedentary person at the same ideal weight have very different health profiles. Weight alone does not tell the whole story.
- Applying these formulas to children or teenagers. These formulas were developed for adults. Children's healthy weight should be assessed using age- and sex-specific BMI percentile charts.
- Using ideal weight as the only health metric. Blood pressure, blood sugar, cholesterol, fitness level, and diet quality all matter independently of weight.
Results are rough estimates based on height and sex only. Not medical advice. Consult a healthcare professional for individualized weight and health guidance.
How we calculate this
Ideal weight is estimated using four classic formulas (Devine, Robinson, Miller, Hamwi) that predict a target weight from height and sex. A healthy weight range is also shown using BMI 18.5–24.9. Results are ballpark estimates based on population data, not individualized medical targets.
Sources
Frequently asked questions
How is ideal weight calculated?
The classic formulas — Devine, Robinson, Miller, and Hamwi — each estimate an ideal body weight from height and sex by starting from a base weight at 5 feet tall and adding a fixed number of pounds for each inch above that. The calculator also shows the healthy weight range derived from a BMI of 18.5–24.9, which gives a broader, evidence-based band.
Which ideal weight formula is the most accurate?
None of these formulas was designed to define the single best weight for an individual. Devine was originally developed for medication dosing in clinical settings; Robinson, Miller, and Hamwi came later as refinements. The healthy BMI range (18.5–24.9) is generally the most useful practical guide for adults, as it is backed by extensive population health research.
Do ideal weight formulas account for muscle mass or body frame?
No. All four classic formulas use only height and sex, so a heavily muscular person and a slight-framed person of the same height get the same result. These are rough benchmarks, not individualized targets. A more complete picture comes from body fat percentage or a conversation with a healthcare provider.
What is the Devine formula?
The Devine formula, published in 1974, calculates ideal weight as 50 kg plus 2.3 kg for each inch over 5 feet for men, and 45.5 kg plus 2.3 kg for each inch over 5 feet for women. It was originally created to estimate lean body mass for drug dosing in pharmacology — not as a weight-loss target.
What is a healthy weight range for my height?
The BMI-based healthy range corresponds to a BMI between 18.5 and 24.9. For a person 5 feet 6 inches tall, that works out to approximately 115–154 lb. The exact range for your height is shown in the calculator output. This range is a statistical guideline for most adults, not a guarantee of health at every weight within it.
Can I be healthy outside the ideal weight range?
Yes. These formulas produce single-point estimates and broad ranges based on population data. An individual with high muscle mass, unusual proportions, or certain health conditions may be perfectly healthy at a weight the formulas flag as above or below ideal. Always interpret these results alongside a healthcare provider's assessment.
How do I use ideal weight in a practical way?
Think of the results as a general orientation, not a fixed target. If your weight is well within the healthy BMI range and your other health markers (blood pressure, blood sugar, cholesterol) are normal, chasing a lower number on an ideal-weight formula offers little benefit. If you are significantly above or below the range, it may be worth discussing goals with a doctor or registered dietitian.