Ideal Weight Calculator
Find your ideal body weight using multiple formulas (Devine, Robinson, Miller, Hamwi). Enter your height and gender. Free health calculator, no signup.
The Four Major Ideal Weight Formulas Compared
Four clinical formulas have been used for decades to estimate ideal body weight (IBW). They were originally developed for medical dosing calculations, not aesthetic goals, so they represent a functional baseline — the weight at which your body operates efficiently.
| Formula | Year | Men (per inch over 5ft) | Women (per inch over 5ft) |
|---|---|---|---|
| Devine | 1974 | 50 kg + 2.3 kg | 45.5 kg + 2.3 kg |
| Robinson | 1983 | 52 kg + 1.9 kg | 49 kg + 1.7 kg |
| Miller | 1983 | 56.2 kg + 1.41 kg | 53.1 kg + 1.36 kg |
| Hamwi | 1964 | 48 kg + 2.7 kg | 45.5 kg + 2.2 kg |
Practical example — 5'10" male (70 inches = 10 inches over 5ft):
- Devine: 50 + (2.3 × 10) = 73 kg (161 lb)
- Robinson: 52 + (1.9 × 10) = 71 kg (157 lb)
- Miller: 56.2 + (1.41 × 10) = 70.3 kg (155 lb)
- Hamwi: 48 + (2.7 × 10) = 75 kg (165 lb)
The range (70–75 kg) shows why no single formula is authoritative — the truth lies within the range, and your ideal weight depends on individual factors beyond height alone.
Ideal Weight Ranges by Height: Quick Reference
The table below shows typical IBW ranges derived from the four formulas. These are starting points — not targets that should override health, fitness, or medical guidance.
| Height | Men (kg) | Men (lb) | Women (kg) | Women (lb) |
|---|---|---|---|---|
| 5'0" (152 cm) | 50–56 | 110–124 | 45–53 | 100–117 |
| 5'2" (157 cm) | 54–61 | 119–135 | 49–57 | 108–126 |
| 5'4" (163 cm) | 58–67 | 128–147 | 53–61 | 117–135 |
| 5'6" (168 cm) | 62–72 | 137–158 | 57–65 | 126–144 |
| 5'8" (173 cm) | 66–76 | 145–168 | 61–69 | 134–152 |
| 5'10" (178 cm) | 70–75 | 154–166 | 64–73 | 142–161 |
| 6'0" (183 cm) | 74–80 | 163–176 | 68–77 | 150–170 |
| 6'2" (188 cm) | 78–85 | 172–187 | 72–81 | 159–179 |
Note: These ranges reflect lean, healthy body composition. Frame size, ethnicity, muscle mass, and age all affect what weight is truly ideal for a given individual.
Why Ideal Weight Formulas Have Limitations
The four IBW formulas share a fundamental limitation: they only account for height and sex. They cannot distinguish between a lean marathon runner and a sedentary person of the same height. Two people at identical weight and height can have vastly different body compositions — one with 15% body fat and one with 35% body fat.
Research published in the American Journal of Clinical Nutrition found that the Devine formula may underestimate ideal weight for taller individuals (above 6'0") and overestimate it for shorter individuals (below 5'4"). Modern clinicians often use IBW as a starting calculation for drug dosing rather than as a fitness goal.
The BMI system has similar limitations — it labels many muscular athletes as "overweight" while missing thin individuals with unhealthy body composition. Body fat percentage, waist circumference, and waist-to-hip ratio provide more complete health pictures than weight alone.
Body Composition: A Better Way to Think About Weight
Rather than targeting a number on the scale, focus on body composition — the ratio of fat mass to lean mass (muscle, bone, organs, water). Healthy body fat ranges by age and sex:
| Category | Men | Women |
|---|---|---|
| Athletes | 6–13% | 14–20% |
| Fitness | 14–17% | 21–24% |
| Acceptable | 18–24% | 25–31% |
| Obese | 25%+ | 32%+ |
Body fat can be measured through DEXA scan (gold standard), hydrostatic weighing, bod pod, skinfold calipers, or bioelectrical impedance (least accurate). Building lean muscle mass shifts body composition favorably — you can weigh the same but be meaningfully healthier and leaner.
A practical goal: lose fat while preserving muscle mass. This usually means a modest caloric deficit (300–500 calories/day) combined with resistance training at least 2–3 times per week. Rapid weight loss (>1 kg/week) tends to include significant muscle loss, which is counterproductive long-term.
Setting Realistic Weight Goals
Understanding your baseline helps set realistic targets. Here's how to use your ideal weight calculation effectively:
- Find your IBW range: Use all four formulas — your realistic target likely falls within that range, ±5–10% depending on your frame.
- Assess current body composition: If you're significantly above IBW, a realistic safe rate of loss is 0.5–1 kg (1–2 lb) per week on a 500–1000 calorie/day deficit.
- Don't over-restrict: Eating below 1,200 calories/day (women) or 1,500 calories/day (men) typically causes muscle loss, nutrient deficiencies, and metabolic adaptation.
- Strength training matters: For every 5 kg of fat you lose, you want to preserve or gain lean mass. Include 2–3 resistance sessions per week.
Example: A 5'6" woman at 75 kg targeting the IBW midpoint of ~61 kg (14 kg to lose) should plan for 14–28 weeks (roughly 3–7 months) with a 500–750 calorie daily deficit — a realistic, sustainable timeline.
Ideal Weight for Athletes and Special Populations
Standard IBW formulas were developed for average sedentary populations and are often inappropriate for:
- Strength athletes and bodybuilders: May carry 5–15 kg more muscle than IBW formulas predict, yet have excellent health markers. Lean muscle mass is metabolically beneficial.
- Endurance runners: Lighter tends to be faster for running economy. Elite marathon runners often run 5–10% below standard IBW, but this isn't a target for recreational athletes without medical supervision.
- Older adults (65+): Some research suggests that slightly higher BMI (25–30) is associated with better outcomes in older populations — the "obesity paradox." Muscle mass preservation is more important than scale weight in this group.
- Pregnant women: IBW calculators should not be used during pregnancy. Weight gain targets depend on pre-pregnancy BMI and are set by your obstetrician.
- Children and adolescents: Use BMI-for-age percentile charts, not adult IBW formulas.
"Maintaining a healthy body weight is associated with reduced risk of cardiovascular disease, type 2 diabetes, and certain cancers. A healthy BMI range (18.5–24.9) serves as a population-level indicator, but individual health should be assessed using multiple measures including waist circumference and metabolic risk factors."
💡 Did you know?
- The Devine Formula (1974) for ideal body weight was originally designed to estimate medication dosages for patients — not as a fitness goal.
- There is no single universal "ideal weight" — optimal weight depends on muscle mass, bone density, age, sex, and ethnicity.
- Studies show "normal weight" individuals can still be metabolically unhealthy, while some "overweight" people have excellent metabolic profiles.
Frequently Asked Questions
Which ideal weight formula is most accurate?
No single formula is definitively most accurate. The Devine formula is most widely used in clinical settings. For a realistic range, compare all four — your healthy weight likely falls within the spread. The Hamwi formula tends to give the highest estimates, while Miller tends to be the lowest.
Is ideal weight the same as healthy weight?
Not exactly. IBW formulas estimate weight based solely on height and sex. A healthy weight also considers body composition, fitness level, age, and metabolic markers like blood glucose, cholesterol, and blood pressure. Someone within the IBW range can still be metabolically unhealthy ("skinny fat").
How much can ideal weight vary from person to person?
Even among people of the same height and sex, healthy weight can vary by 10–20 kg depending on frame size (small, medium, large), muscle mass, bone density, and ethnicity. Some research shows Asian populations may have better health outcomes at lower BMIs than Western-derived formulas suggest.
What if I'm within the ideal weight range but still feel unfit?
Weight is not the same as fitness. You can be at ideal weight with low muscle mass and poor cardiovascular fitness. Focus on functional measures: can you climb stairs without breathlessness? Do you have energy throughout the day? Regular aerobic and strength exercise improves health markers independent of weight.
How does age affect ideal weight?
IBW formulas don't adjust for age, but in practice some weight gain with age (up to ~1–2 BMI points) may be normal and not harmful, especially if it reflects maintained muscle mass rather than excess fat. After 30, muscle mass naturally declines 3–8% per decade without resistance training — meaning the same weight may carry more fat.
Can I use this calculator for weight gain goals?
Yes. If you're underweight (below your IBW range), a slow, consistent surplus of 250–500 calories/day combined with strength training is the safest way to gain lean mass. Rapid weight gain tends to add more fat than muscle. Aim for 0.25–0.5 kg per week.
Are IBW formulas applicable to all ethnicities?
The formulas were largely derived from Western populations. Research shows that people of Asian descent tend to have higher body fat at the same BMI and IBW. South Asian and East Asian health guidelines often use lower BMI thresholds (23 for overweight vs 25 in Western guidelines) to better reflect cardiovascular risk.
Waist-to-Height Ratio: A Better Predictor Than BMI or IBW
Recent research suggests that the waist-to-height ratio (WHtR) may be a superior predictor of cardiovascular disease risk compared to both BMI and ideal body weight formulas. The calculation is simple: divide your waist circumference by your height (both in the same unit). A WHtR above 0.5 indicates increased cardiometabolic risk regardless of BMI.
| WHtR Range | Risk Level | Interpretation |
|---|---|---|
| Below 0.4 | Underweight risk | May indicate insufficient body fat or muscle mass |
| 0.4–0.49 | Healthy | Optimal range for cardiometabolic health |
| 0.5–0.59 | Increased risk | Elevated visceral fat; lifestyle changes recommended |
| 0.6+ | High risk | Significantly elevated cardiovascular and diabetes risk |
A 2024 meta-analysis published in BMC Medicine analyzing over 600,000 adults found that WHtR predicted cardiovascular events and type 2 diabetes more accurately than BMI in both men and women across all ethnicities studied. The "keep your waist circumference to less than half your height" guideline is easy to remember and applies universally, unlike BMI cutoffs that vary by ethnicity.
The advantage of WHtR over IBW formulas is that it directly assesses central adiposity — the visceral fat around organs that drives metabolic disease. Two people at the same IBW can have vastly different WHtR values, and the one with higher visceral fat faces significantly greater health risks. Measure your waist at the narrowest point between your ribs and hip bones (usually at the navel), standing relaxed, at the end of a normal exhale.
Metabolic Health Markers Beyond the Scale
Reaching your ideal weight is meaningless if your metabolic health markers are poor. Research from the European Heart Journal shows that roughly 30% of normal-weight adults are "metabolically unhealthy" — they carry normal scale weight but have elevated blood pressure, blood sugar, triglycerides, or low HDL cholesterol. Conversely, about 20% of overweight individuals (BMI 25–30) are "metabolically healthy" with normal lab values.
Key metabolic markers to track alongside weight:
- Fasting glucose: Under 100 mg/dL (5.6 mmol/L) is normal; 100–125 mg/dL is pre-diabetic
- HbA1c: Under 5.7% is normal; reflects 3-month average blood sugar
- Triglycerides: Under 150 mg/dL (1.7 mmol/L) is normal
- HDL cholesterol: Above 40 mg/dL for men, above 50 mg/dL for women
- Blood pressure: Under 120/80 mmHg is optimal
- Waist circumference: Under 102 cm (men), under 88 cm (women) per WHO guidelines
If your metabolic markers are healthy and you're physically active, being 5–10% above your calculated IBW is likely not a health concern. Focus on these markers and your fitness level rather than obsessing over matching a single number from a formula developed in the 1970s. Annual blood work provides far more actionable health information than any scale reading.
For runners specifically, maintaining healthy metabolic markers while staying within a functional weight range for performance is the ideal approach. A competitive distance runner might perform best at the lower end of their IBW range, while a recreational jogger focused on general health can comfortably sit at the higher end. The key is finding the weight where you feel energetic, recover well from training, and maintain healthy lab values — that intersection is your true ideal weight, regardless of what any formula calculates.