Ideal Weight Calculator
5 Medical Formulas · Metric & Imperial
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Enter your height to see your ideal weight across 5 medical formulas.
Average Ideal Weight
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lbs (average of 4 formulas)
The 5 Ideal Weight Formulas Explained
For a 5'10" man the four classic formulas give 155 to 165 lb, an average of 159 lb; for a 5'6" woman they give 129 to 135 lb, an average of 131 lb. Devine, the formula most used in medicine, is 50 kg for men or 45.5 kg for women plus 2.3 kg per inch over 5 feet. Enter your height and sex above to compare all four.
Ideal body weight (IBW) formulas were originally developed for clinical use: primarily for calculating medication dosages, anaesthesia doses, and ventilator settings. They were never intended as definitive "target weights" for the general population. Each formula uses only height and sex, making them simple but limited tools that ignore muscle mass, body frame, and age.
| Formula | Year | Men (base + per inch) | Women (base + per inch) | Primary Use |
|---|---|---|---|---|
| Devine | 1974 | 50 kg + 2.3 kg/in | 45.5 kg + 2.3 kg/in | Drug dosing, most widely used |
| Robinson | 1983 | 52 kg + 1.9 kg/in | 49 kg + 1.7 kg/in | Modified Devine, broader use |
| Miller | 1983 | 56.2 kg + 1.41 kg/in | 53.1 kg + 1.36 kg/in | Conservative estimate |
| Hamwi | 1964 | 48 kg + 2.7 kg/in | 45.5 kg + 2.2 kg/in | Dietetics and nutrition |
| BMI Range | — | 18.5 to 24.9 × height (m)² | General population health | |
All formulas calculate weight for heights above 5 feet (152 cm) in imperial units. For heights below 5 feet, the calculations become less reliable. The BMI-based range (18.5-24.9) is currently the most evidence-backed approach for general population weight assessment, though it shares the same limitation of not accounting for body composition.
Why Formulas Differ
Each formula was derived from a different research population and clinical context. Devine was based on a drug dosing study from the 1970s. Robinson and Miller updated the Devine formula with larger datasets. Hamwi was developed for dietetics. None were designed as population health targets, the differences reflect the imprecision inherent in reducing a complex individual to two variables: height and sex.
Frame Size Adjustment
Some practitioners adjust ideal weight by 10% for frame size. Small frame: subtract 10%. Medium frame: use as-is. Large frame: add 10%. Frame size can be estimated by measuring wrist circumference. For women under 5'2": small (<5.5 in), medium (5.5 to 5.75 in), large (>5.75 in); the cut-offs rise with height (see the frame size table below). For men over 5'5": small (<6.5 in), medium (6.5-7.5 in), large (>7.5 in). This adjustment accounts somewhat for bone density differences.
Healthy Weight vs Ideal Weight
Ideal weight (from formulas) and healthy weight (BMI 18.5-24.9) are not identical. The formula-derived IBW typically falls in the lower-to-middle portion of the BMI healthy range. A person can be healthy at any weight within the BMI 18.5-24.9 range. The IBW formulas were designed for clinical utility, not aesthetic or personal goals: treat them as one data point, not a target.
Athletes and Muscular Individuals
All ideal weight formulas will underestimate appropriate weight for highly muscular individuals. A 5'10" competitive athlete with 8% body fat may weigh 200+ lbs, far above the 155 to 165 lb the four formulas give for that height. For athletic populations, body fat percentage (target 6-17% men, 14-24% women for fitness) is a more appropriate metric than formula-derived ideal weight. Use IBW as a general reference only.
Ideal Weight Chart by Height
Every figure below comes from the same formulas the calculator uses, rounded to the nearest pound.
Men
| Height | Devine | Robinson | Miller | Hamwi | Average | BMI healthy range |
|---|---|---|---|---|---|---|
| 5'0" | 110 lb | 115 lb | 124 lb | 106 lb | 114 lb | 95 to 127 lb |
| 5'2" | 120 lb | 123 lb | 130 lb | 118 lb | 123 lb | 101 to 136 lb |
| 5'4" | 131 lb | 131 lb | 136 lb | 130 lb | 132 lb | 108 to 145 lb |
| 5'6" | 141 lb | 140 lb | 143 lb | 142 lb | 141 lb | 115 to 154 lb |
| 5'8" | 151 lb | 148 lb | 149 lb | 153 lb | 150 lb | 122 to 164 lb |
| 5'10" | 161 lb | 157 lb | 155 lb | 165 lb | 159 lb | 129 to 174 lb |
| 6'0" | 171 lb | 165 lb | 161 lb | 177 lb | 169 lb | 136 to 184 lb |
| 6'2" | 181 lb | 173 lb | 167 lb | 189 lb | 178 lb | 144 to 194 lb |
| 6'4" | 191 lb | 182 lb | 174 lb | 201 lb | 187 lb | 152 to 205 lb |
Women
| Height | Devine | Robinson | Miller | Hamwi | Average | BMI healthy range |
|---|---|---|---|---|---|---|
| 5'0" | 100 lb | 108 lb | 117 lb | 100 lb | 106 lb | 95 to 127 lb |
| 5'2" | 110 lb | 116 lb | 123 lb | 110 lb | 115 lb | 101 to 136 lb |
| 5'4" | 121 lb | 123 lb | 129 lb | 120 lb | 123 lb | 108 to 145 lb |
| 5'6" | 131 lb | 131 lb | 135 lb | 129 lb | 131 lb | 115 to 154 lb |
| 5'8" | 141 lb | 138 lb | 141 lb | 139 lb | 140 lb | 122 to 164 lb |
| 5'10" | 151 lb | 146 lb | 147 lb | 149 lb | 148 lb | 129 to 174 lb |
| 6'0" | 161 lb | 153 lb | 153 lb | 159 lb | 156 lb | 136 to 184 lb |
Notice how the formulas spread apart at the ends. At 6'4" the male estimates run from 174 lb (Miller) to 201 lb (Hamwi), a 27 lb gap, because Hamwi adds 2.7 kg per inch and Miller only 1.41 kg.
Worked Example: a 5'10" Man
Height over 5 feet: 70 − 60 = 10 inches.
- Devine: 50 + 2.3 × 10 = 73 kg, or 161 lb.
- Robinson: 52 + 1.9 × 10 = 71 kg, or 157 lb.
- Miller: 56.2 + 1.41 × 10 = 70.3 kg, or 155 lb.
- Hamwi: 48 + 2.7 × 10 = 75 kg, or 165 lb.
- Average: (73 + 71 + 70.3 + 75) ÷ 4 = 72.3 kg, or 159 lb.
Hamwi first wrote his rule in pounds: 106 lb for a man at 5 feet plus 6 lb per inch, and 100 lb for a woman plus 5 lb per inch. The metric version used here gives nearly the same result (165 lb against 166 lb for this man).
Frame Size and Short Stature
A common adjustment is to take 10% off the result for a small frame and add 10% for a large frame. MedlinePlus uses wrist circumference and height to judge frame size:
| Group | Small frame | Medium frame | Large frame |
|---|---|---|---|
| Women under 5'2" | under 5.5 in | 5.5 to 5.75 in | over 5.75 in |
| Women 5'2" to 5'5" | under 6 in | 6 to 6.25 in | over 6.25 in |
| Women over 5'5" | under 6.25 in | 6.25 to 6.5 in | over 6.5 in |
| Men over 5'5" | 5.5 to 6.5 in | 6.5 to 7.5 in | over 7.5 in |
Example: a 5'6" woman with a 6 inch wrist has a small frame, so 131 lb becomes about 118 lb, still inside her BMI healthy range of 115 to 154 lb.
All four formulas start at 5 feet. For anyone shorter, the calculator shows the 5 foot value (for example 100 lb for a woman on Devine), which is likely too high, so use the BMI range as the better guide. Ideal weight numbers are estimates. A doctor or registered dietitian can tell you what weight makes sense for you. For a check on body fat itself, see the body fat calculator.
Method and sources. Devine BJ (1974), Robinson JD et al. (1983), Miller DR et al. (1983) and Hamwi GJ (1964), with height over 5 feet in inches and weight in kg; 1 kg = 2.20462 lb. BMI healthy range 18.5 to 24.9 from CDC and WHO. Frame size: MedlinePlus (NIH National Library of Medicine). Every table value was computed with the same formulas as the calculator. Estimates only, not medical advice.
Ideal weight formulas are clinical estimation tools, not personal weight targets. Healthy weight varies by individual. Consult a healthcare professional or registered dietitian for personalized guidance.
Frequently Asked Questions
No single formula is universally "most accurate": each was developed for different clinical contexts. The Devine formula (1974) is the most widely used in clinical settings, particularly for drug dosing, anaesthesia, and ventilator tidal volume calculations. The Hamwi formula is popular in dietetics. BMI-based ranges (18.5-24.9) are the most evidence-backed approach for general population health assessment. Using an average of multiple formulas gives a more balanced estimate. For personal weight goals, your doctor or registered dietitian can provide guidance specific to your health history and body composition.
Weight ranges by height (men): 5'6" = 140 to 154 lbs, 5'8" = 148 to 164 lbs, 5'10" = 155 to 174 lbs, 6'0" = 161 to 184 lbs. For women the lower end runs about 10 lbs lighter at the same height, while the BMI ceiling is the same. These ranges represent the span between the lowest formula estimate and the top of the BMI healthy range. Body weight is highly individual: two people at the same height can be equally healthy at significantly different weights depending on muscle mass, bone density, and body frame. Enter your exact height in the calculator above for formula-specific estimates.
Standard ideal weight formulas do not account for muscle mass or bone density. They use only height and sex. A bodybuilder and a sedentary person of the same height would get identical "ideal weight" results despite having vastly different body compositions. Frame size adjustments of plus or minus 10% are sometimes applied to account for large or small skeletal frames. For muscular individuals, body fat percentage is a far more meaningful measurement than ideal weight. Athletes at 200 lbs may be leaner and healthier than a sedentary person at their "ideal" 165 lbs.
The Devine formula, published by B.J. Devine in 1974, calculates: Men: 50 kg + 2.3 kg for each inch over 5 feet. Women: 45.5 kg + 2.3 kg for each inch over 5 feet. Example for a 5'10" male: 50 + (2.3 × 10) = 50 + 23 = 73 kg (161 lbs). For a 5'6" female: 45.5 + (2.3 × 6) = 45.5 + 13.8 = 59.3 kg (131 lbs). It was originally developed for drug dosing calculations, not as a weight loss target, which is often misunderstood.
Ideal weight (single number from a formula) and healthy weight range (BMI 18.5-24.9 span) serve different purposes. The IBW formulas produce a single point estimate designed for clinical calculations. The BMI healthy range defines a band. For a 5'10" male, that is 129 to 174 lbs, a 45-pound range. IBW formulas typically land in the lower-to-middle portion of this range. Neither approach is a target you must hit. Being anywhere within the BMI healthy range is associated with similar health outcomes. Pursuing a specific "ideal weight" number is less clinically meaningful than maintaining body fat percentage and metabolic health within healthy ranges.
Standard IBW formulas do not include age as a variable. However, research suggests that slightly higher BMI (25-27) may be protective for adults over 65, as it provides reserves against illness, muscle wasting (sarcopenia), and recovery from surgery or illness. The weight that is best for a 70-year-old may be higher than these formulas suggest. For older adults, maintaining muscle mass through resistance training matters more than achieving a specific scale weight. The formulas remain most applicable and most accurate for adults aged 20-60.
For a 5'10" (178 cm) male: Devine formula gives 73 kg (161 lbs), Robinson gives 71 kg (157 lbs), Miller gives 70.3 kg (155 lbs), Hamwi gives 75 kg (165 lbs). The average of the four formulas is about 159 lbs (72.3 kg). The BMI healthy range for this height is 129 to 174 lbs (58.5 to 78.7 kg). Lean, muscular men can be healthy above this range. Use the calculator above for your exact measurements.
For a 5'6" (168 cm) female: Devine formula gives 59.3 kg (131 lbs), Robinson gives 59.2 kg (131 lbs), Miller gives 61.3 kg (135 lbs), Hamwi gives 58.7 kg (129 lbs). Average across formulas: about 131 lbs (59.6 kg). BMI healthy range for this height is 115 to 154 lbs (52 to 70 kg). Women with higher muscle mass from athletic training may be healthy at 155-165 lbs at this height.
Ideal weight formulas are clinical reference points, not personal targets. Research on weight and health shows that metabolic health markers (blood glucose, blood pressure, cholesterol, triglycerides) matter more than scale weight alone. A person can have a "normal" BMI or ideal weight and have poor metabolic health, and vice versa. Instead of targeting a specific number, most evidence supports focusing on: regular physical activity (150+ minutes of moderate exercise per week), strength training to build and preserve muscle, a balanced whole-food diet, adequate sleep, and stress management. If weight loss is a health goal, a registered dietitian can help set realistic, evidence-based targets.
The formulas differ because they were each derived from different research populations in different decades. Devine (1974) based his formula on a clinical observation study. Robinson et al. (1983) reanalyzed height and weight data from life insurance tables, arriving at different constants. Miller et al. (1983) used yet another dataset. Hamwi (1964) developed a rule-of-thumb for dietitians. No formula is "correct" in an objective sense: they reflect different snapshots of population data and different methodological choices. The spread between formulas (typically 5-15 lbs at most heights) illustrates the inherent imprecision of reducing individual body weight to a single height-based estimate.
The four formulas give 161 to 177 lb for a 6'0" man: Devine 171 lb, Robinson 165 lb, Miller 161 lb and Hamwi 177 lb, an average of 169 lb. The BMI healthy range at that height is wider, 136 to 184 lb. Muscular men can be healthy above both.
For a 5'4" woman the formulas give 120 to 129 lb: Devine 121 lb, Robinson 123 lb, Miller 129 lb and Hamwi 120 lb, an average of 123 lb. The BMI healthy range for that height is 108 to 145 lb.