Ideal Weight Calculator
Ideal body weight formulas start with a fixed weight for 5 feet of height and add a set amount per inch above it. With the Devine formula, a 5 ft 6 in woman gets 45.5 + 2.3 × 6 = 59.3 kg (about 130.7 lb), and a man of that height gets 63.8 kg. The ideal weight calculator below compares four formulas with the CDC healthy-weight range.
For adults (18 and older). Height 4 ft 6 in to 7 ft 6 in (137.2 to 228.6 cm). Add your current weight to see your BMI, where you sit in the CDC range and the adjusted body weight.
or 58.7 to 61.3 kg
For a woman who is 5 ft 6 in tall, the Devine, Robinson, Miller and Hamwi formulas give 129.4 to 135.1 lb (Devine: 130.7 lb). The CDC healthy-weight range for this height is 115 to 154 lb.
Dashed red line: your current weight, 160.0 lb
| Formula (women) | With your height | kg | lb |
|---|---|---|---|
| Devine1974, most used clinically | 45.5 + 2.3 × 6 | 59.3 | 130.7 |
| Robinson1983 | 49 + 1.7 × 6 | 59.2 | 130.5 |
| Miller1983 | 53.1 + 1.36 × 6 | 61.3 | 135.1 |
| Hamwi1964 | 45.5 + 2.2 × 6 | 58.7 | 129.4 |
These are clinical estimation formulas, not weight goals. Devine and the others were built to help dose medicines and estimate nutrition needs, and they ignore age, muscle, frame size and health history. The CDC range is a screening range based on BMI. Results are estimates, not medical advice; a healthcare provider can help you decide what a healthy weight means for you.
Show steps
- Write the height in inches: 5 ft × 12 + 6 in = 66 in. Every formula starts at 5 ft (60 in), so the inches over 5 ft are 66 − 60 = 6.
- Devine (1974, women): 45.5 kg for the first 5 ft, plus 2.3 kg per inch. 45.5 + 2.3 × 6 = 45.5 + 13.8 ≈ 59.3 kg.
- Robinson (1983, women): 49 kg for the first 5 ft, plus 1.7 kg per inch. 49 + 1.7 × 6 = 49 + 10.2 ≈ 59.2 kg.
- Miller (1983, women): 53.1 kg for the first 5 ft, plus 1.36 kg per inch. 53.1 + 1.36 × 6 = 53.1 + 8.16 ≈ 61.3 kg.
- Hamwi (1964, women): 45.5 kg for the first 5 ft, plus 2.2 kg per inch. 45.5 + 2.2 × 6 = 45.5 + 13.2 ≈ 58.7 kg.
- To change kilograms to pounds, divide by 0.45359237. For Devine: 59.3 ÷ 0.45359237 ≈ 130.7 lb. The range of the four formulas is 58.7 to 61.3 kg, or 129.4 to 135.1 lb.
- CDC healthy-weight range: BMI 18.5 to 24.9, so the BMI must be at least 18.45 and below 24.95 before rounding. Weight = BMI × height (in)² ÷ 703: 18.45 × 4,356 ÷ 703 ≈ 114.32 lb and 24.95 × 4,356 ÷ 703 ≈ 154.6 lb. Rounded inward to whole pounds, that is 115 to 154 lb.
- Your weight in kilograms: 160 × 0.45359237 ≈ 72.57 kg. Your BMI is 703 × 160 ÷ 4,356 ≈ 25.8.
- Percent of ideal body weight: 72.57 ÷ 59.3 × 100 ≈ 122%.
- Adjusted body weight adds 40% of the extra weight to IBW: ABW = IBW + 0.4 × (actual − IBW) = 59.3 + 0.4 × (72.57 − 59.3) ≈ 64.6 kg, or 142.4 lb.
How to use the ideal weight calculator
- Choose Female or Male. Each formula has a different starting weight and step for men and women.
- Pick US units (feet and inches) or metric units (centimeters) and enter your height. Switching units converts what you typed.
- Optionally add your current weight to see your BMI and adjusted body weight.
- Read the range of the four formulas, the number line and the table, or open Show steps for the full working.
The results are estimates for adults, not medical advice. These are clinical estimation formulas, not weight goals: they were made to help dose medicines and estimate nutrition needs, and they know nothing about your age, muscle, frame size or health. A healthcare provider can help you decide what a healthy weight means for you.
Ideal body weight formulas: Devine, Robinson, Miller and Hamwi
All four formulas have the same shape. In each one, h is the number of inches over 5 feet (height in inches − 60), and the answer is in kilograms. To change kilograms to pounds, divide by 0.45359237.
| Formula | Men (kg) | Women (kg) | Built from |
|---|---|---|---|
| Devine (1974) | 50 + 2.3h | 45.5 + 2.3h | An older rule of thumb, for drug dosing |
| Robinson (1983) | 52 + 1.9h | 49 + 1.7h | 1959 Metropolitan Life height-weight tables |
| Miller (1983) | 56.2 + 1.41h | 53.1 + 1.36h | 1983 Metropolitan Life height-weight tables |
| Hamwi (1964) | 48 + 2.7h | 45.5 + 2.2h | A pound-based rule of thumb |
Hamwi’s rule is usually quoted in pounds: 106 lb for the first 5 feet plus 6 lb per inch for men, and 100 lb plus 5 lb per inch for women, with 10% added or subtracted for a large or small frame. The kilogram version in the table is the same rule rounded. Robinson’s paper reports the unrounded fits as 51.65 + 1.85h for men and 48.67 + 1.65h for women; the rounded form above is the one clinicians use.
Where the formulas came from
Pai and Paloucek explain that height-weight tables were first made to compare people’s weights, and the weights linked with the lowest death rates became labeled “desirable” or “ideal.” Devine published his equations in 1974 to estimate kidney clearance for the antibiotic gentamicin; they were not fitted to a data set. Robinson and Miller later fitted straight lines to life-insurance height-weight tables. The formulas agree closely because the tables behind them agree, and the review concludes that any one of them may be used to estimate IBW. Devine is the version most clinical calculators use, including MDCalc and ClinCalc.
Ideal weight vs the CDC healthy BMI range
The CDC does not publish a single ideal weight. For adults it gives a healthy-weight range based on body mass index: a BMI of 18.5 to less than 25, which is 18.5 to 24.9 when BMI is rounded to one decimal. To turn that into weights for one height, rearrange the BMI formula: weight (lb) = BMI × height (in)² ÷ 703. For 5 ft 6 in (66 in), 66² = 4,356, so 18.45 × 4,356 ÷ 703 ≈ 114.3 lb and 24.95 × 4,356 ÷ 703 ≈ 154.6 lb. In whole pounds, the range is 115 to 154 lb. The four IBW formulas all land inside it, near the middle.
Healthy people of the same height differ in muscle, bone and build, so a range is more honest than one number. Our BMI calculator shows every CDC category for your height.
Worked ideal weight examples
Example 1: a woman, 5 ft 6 in
Height is 5 × 12 + 6 = 66 in, so h = 66 − 60 = 6. Devine: 45.5 + 2.3 × 6 = 59.3 kg. Robinson: 49 + 1.7 × 6 = 59.2 kg. Miller: 53.1 + 1.36 × 6 = 61.26 ≈ 61.3 kg. Hamwi: 45.5 + 2.2 × 6 = 58.7 kg. In pounds, the four formulas give 129.4 to 135.1 lb, and the CDC healthy-weight range at this height is 115 to 154 lb.
Example 2: a man, 180 cm
First change centimeters to inches: 180 ÷ 2.54 ≈ 70.87 in, so h ≈ 10.87. Devine: 50 + 2.3 × 10.87 ≈ 75.0 kg. Robinson: 52 + 1.9 × 10.87 ≈ 72.6 kg. Miller: 56.2 + 1.41 × 10.87 ≈ 71.5 kg. Hamwi: 48 + 2.7 × 10.87 ≈ 77.3 kg. The CDC healthy-weight range for 180 cm is 59.8 to 80.8 kg.
Example 3: adjusted body weight
A man is 5 ft 10 in and weighs 250 lb. His Devine IBW is 50 + 2.3 × 10 = 73.0 kg (160.9 lb). His actual weight is 250 × 0.45359237 ≈ 113.4 kg, which is 113.4 ÷ 73.0 ≈ 155% of IBW. Adjusted body weight = 73.0 + 0.4 × (113.4 − 73.0) ≈ 89.2 kg, or about 196.6 lb.
Ideal weight chart by height
Devine IBW for men and women next to the CDC healthy-weight range (BMI 18.5 to 24.9) at each height. All values are worked out with the same rounding as the calculator.
| Height | Women, Devine | Men, Devine | CDC healthy range |
|---|---|---|---|
| 5 ft 0 in | 100.3 lb (45.5 kg) | 110.2 lb (50.0 kg) | 95 to 127 lb |
| 5 ft 2 in | 110.5 lb (50.1 kg) | 120.4 lb (54.6 kg) | 101 to 136 lb |
| 5 ft 4 in | 120.6 lb (54.7 kg) | 130.5 lb (59.2 kg) | 108 to 145 lb |
| 5 ft 6 in | 130.7 lb (59.3 kg) | 140.7 lb (63.8 kg) | 115 to 154 lb |
| 5 ft 8 in | 140.9 lb (63.9 kg) | 150.8 lb (68.4 kg) | 122 to 164 lb |
| 5 ft 10 in | 151.0 lb (68.5 kg) | 160.9 lb (73.0 kg) | 129 to 173 lb |
| 6 ft 0 in | 161.2 lb (73.1 kg) | 171.1 lb (77.6 kg) | 137 to 183 lb |
| 6 ft 2 in | 171.3 lb (77.7 kg) | 181.2 lb (82.2 kg) | 144 to 194 lb |
| 6 ft 4 in | 181.4 lb (82.3 kg) | 191.4 lb (86.8 kg) | 152 to 204 lb |
Adjusted body weight explained
Adjusted body weight (ABW) sits between ideal and actual weight. It adds 40% of the weight above IBW:
ABW = IBW + 0.4 × (actual weight − IBW)
Clinicians use it for some drug doses and nutrition calculations when a person’s actual weight is well above IBW, where neither IBW nor full body weight fits well. ClinCalc describes using it when actual weight is more than about 20% above IBW, and notes that protocols differ; some nutrition calculations use a 25% factor instead of 40%. When actual weight is at or below IBW, the actual weight is used.
Limitations of ideal weight formulas
- They use only height and sex. Age, muscle, frame size and body fat are ignored.
- They come from life-insurance tables and old rules of thumb.
- They were written for adults 5 ft and taller.
- A 2016 study by Peterson and colleagues found that the older equations do not line up with BMI and can over- or underestimate at very short and very tall heights.
Common ideal body weight mistakes
- Using total inches instead of inches over 5 ft. For 5 ft 6 in, h is 6, not 66.
- Reading kilograms as pounds. The formulas give kilograms; 59.3 kg is about 130.7 lb, not 59.3 lb.
- Treating IBW as a goal. It is a dosing and nutrition estimate. The CDC range is the better guide to a healthy span of weights.
Sources
Checked November 2026.
- Pai MP, Paloucek FP. The origin of the “ideal” body weight equations. Ann Pharmacother. 2000;34(9):1066-1069
- Robinson JD et al. Determination of ideal body weight for drug dosage calculations. Am J Hosp Pharm. 1983;40(6):1016-1019
- Peterson CM et al. Universal equation for estimating ideal body weight and body weight at any BMI. Am J Clin Nutr. 2016;103(5):1197-1203
- MDCalc: Ideal Body Weight and Adjusted Body Weight
- ClinCalc: Ideal Body Weight Calculator (Devine, adjusted body weight)
- Colson J, Harris S. Introduction to Nutrition and Wellness, 2nd ed.: Assessing Body Weight (Hamwi method)
- CDC: Adult BMI Categories
- CDC: Frequently Asked Questions about BMI
Ideal weight practice quiz: 10 questions
Test yourself with 10 multiple-choice questions. Choose an answer and press Submit to see if you are right and why. Your score appears at the end.
5 ft 4 in is 64 in, which is 4 in over 5 ft. Devine for women: 45.5 + 2.3 × 4 = 54.7 kg. Using all 64 inches gives 45.5 + 147.2 = 192.7 kg, and 59.2 kg is the Devine value for a man.
6 ft 0 in is 72 in, or 12 in over 5 ft: 50 + 2.3 × 12 = 77.6 kg. The answer is in kilograms, not pounds (77.6 kg is about 171.1 lb).
Every formula starts with a weight for 5 feet (60 in) and adds a step for each inch above that, so h = height in inches − 60.
5 ft 8 in is 8 in over 5 ft. Robinson for women: 49 + 1.7 × 8 = 49 + 13.6 = 62.6 kg. Devine would give 63.9 kg and Miller about 64.0 kg; 49.0 kg forgets the per-inch step.
Divide kilograms by 0.45359237 to get pounds: 59.3 ÷ 0.45359237 ≈ 130.7 lb. Multiplying instead gives 26.9, and simply doubling gives 118.6.
ABW = IBW + 0.4 × (actual − IBW) = 70 + 0.4 × 30 = 70 + 12 = 82 kg. Using 0.6 instead of 0.4 gives 88 kg, and 100 kg is the actual weight, not the adjusted one.
Weight = BMI × height (in)² ÷ 703. With 66² = 4,356: 18.45 × 4,356 ÷ 703 ≈ 114.3 and 24.95 × 4,356 ÷ 703 ≈ 154.6, so the whole-pound range is 115 to 154 lb.
Devine offered them to estimate kidney clearance for gentamicin dosing. They were later used for many other clinical calculations, but they were never meant as personal weight goals.
Devine, Robinson, Miller and Hamwi use only height and sex. They ignore age, muscle, frame and body fat, and the CDC does not use them as targets.
5 ft 7 in is 7 in over 5 ft: 106 + 6 × 7 = 106 + 42 = 148 lb. The women's rule (100 + 5 × 7) gives 135 lb, 113 lb forgets to multiply by 6, and 142 lb counts only 6 inches.
Quiz complete
Frequently asked questions
What is my ideal weight for my height?
There is no single ideal weight. The four clinical formulas give a narrow band, for example 129.4 to 135.1 lb for a woman who is 5 ft 6 in, while the CDC healthy-weight range for that height is wider, 115 to 154 lb. Enter your height above to see both.
Which ideal weight formula is most accurate?
None is clearly more accurate for an individual. The formulas are similar because they come from similar height-weight tables, so any one may be used. Devine is the version most clinical tools use.
Is ideal body weight the same as a healthy weight?
No. IBW is a single number used in medical calculations. A healthy weight is a range, and the CDC defines it for adults as a BMI of 18.5 to 24.9. Your healthcare provider can tell you what range makes sense for you.
What is adjusted body weight used for?
It is used to dose some medicines and estimate nutrition needs when a person weighs well above their IBW. It equals IBW plus 40% of the extra weight.
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