This ideal body weight calculator gives your IBW from the four formulas used in medicine: Devine, Robinson, Miller and Hamwi. Enter height and sex, and you get each result in kg, their average and, if you add your current weight, your adjusted body weight.
Ideal body weight is a clinical tool first. Doctors and pharmacists use it to dose some medicines, set ventilator volumes and estimate kidney function. For a personal weight goal, the healthy BMI range on the ideal weight calculator is the better guide.
Quick numbers
Devine, men
50 kg + 2.3 kg per inch over 5 ftDevine, women
45.5 kg + 2.3 kg per inch over 5 ftMetric form
+ 0.91 kg per cm over 152.4 cmAdjusted body weight
IBW + 0.4 × (actual − IBW)Valid for
adults about 5 ft and taller
Ideal body weight calculator formulas, all four
| Formula | Men | Women |
|---|---|---|
| Devine | 50 + 2.3 per inch over 5 ft | 45.5 + 2.3 per inch |
| Robinson | 52 + 1.9 per inch | 49 + 1.7 per inch |
| Miller | 56.2 + 1.41 per inch | 53.1 + 1.36 per inch |
| Hamwi | 48 + 2.7 per inch | 45.5 + 2.2 per inch |
Each began as a quick bedside rule and was later checked against large data sets. Devine is the one most hospitals use. Robinson and Miller were fitted to life insurance and population data and give gentler slopes.
Ideal body weight formula in cm
Men: IBW = 50 + 0.91 × (height in cm − 152.4)
Women: IBW = 45.5 + 0.91 × (height in cm − 152.4)
A woman of 160 cm: 45.5 + 0.91 × 7.6 = 52.4 kg. A man of 175 cm: 50 + 0.91 × 22.6 = 70.6 kg.
This is the Devine formula in metric form, the same one intensive care teams use as predicted body weight.
Ideal body weight chart
| Height | Women, Devine | Women, Robinson | Men, Devine | Men, Robinson |
|---|---|---|---|---|
| 5'0 (152 cm) | 45.5 | 49.0 | 50.0 | 52.0 |
| 5'2 (157 cm) | 50.1 | 52.4 | 54.6 | 55.8 |
| 5'4 (163 cm) | 54.7 | 55.8 | 59.2 | 59.6 |
| 5'6 (168 cm) | 59.3 | 59.2 | 63.8 | 63.4 |
| 5'8 (173 cm) | 63.9 | 62.6 | 68.4 | 67.2 |
| 5'10 (178 cm) | 68.5 | 66.0 | 73.0 | 71.0 |
| 6'0 (183 cm) | 73.1 | 69.4 | 77.6 | 74.8 |
Single heights have their own pages with BMI ranges too, for example 5'4 and 5'10.
How to calculate ideal body weight by hand
- Write your height in inches (1 inch = 2.54 cm).
- Subtract 60 to get inches over 5 feet.
- Multiply by 2.3 for the Devine formula.
- Add 50 for a man or 45.5 for a woman.
Say a man stands 5 feet 9 inches: 9 × 2.3 = 20.7, plus 50, gives 70.7 kg.
Adjusted body weight
When actual weight is well above IBW, some drug doses use adjusted body weight: IBW + 0.4 × (actual weight − IBW). For a man with an IBW of 70.7 kg who weighs 95 kg, that is 70.7 + 0.4 × 24.3 = 80.4 kg. This is for clinicians; do not change your own medicine doses from it.
Ideal body weight for women and men
The formulas give women about 4.5 kg less than men at the same height, reflecting less muscle and bone. For most adults, IBW falls inside the healthy BMI range, often in its middle. Very muscular people and those with large frames will sit above it without any health problem.
Limits of ideal body weight
- It ignores frame size, muscle and body shape.
- It was built mostly from Western data.
- It is not meant for people shorter than 5 feet; results get odd below that.
- It says nothing about fat distribution, which matters a lot for South Asians.
For a target that fits your health, pair BMI with a tape around the waist, or estimate body composition with the body fat calculator.
If a doctor has given you a dosing weight or a target weight, follow their figure. They know your full history.
Frequently asked questions
What is ideal body weight?
A reference weight for your height and sex from formulas such as Devine. It is used mainly for medical dosing and as a rough guide.
How do I calculate ideal body weight?
For men, 50 kg plus 2.3 kg for each inch over 5 feet; for women, 45.5 kg plus 2.3 kg per inch.
What is the ideal body weight formula in kg?
Devine in metric: 50 (men) or 45.5 (women) + 0.91 × (height in cm − 152.4).
Which ideal body weight formula is best?
Devine is the clinical standard. Robinson and Miller give slightly different figures; none accounts for muscle.
Does IBW equal a healthy weight?
Not exactly. Healthy weight is a range from BMI; IBW is a single figure that usually sits inside it.
What is the ideal body weight according to height for women?
At 5 feet, 45.5 kg; at 5 feet 4 inches, about 54.7 kg; at 5 feet 6 inches, about 59.3 kg by Devine.
Sources
- Devine, Robinson, Miller and Hamwi ideal body weight formulas