BMI Calculator
Body Mass Index (BMI) is your weight in kilograms divided by the square of your height in metres (kg/m²), and a BMI between 18.5 and 24.9 is considered healthy for most adults. Enter your height and weight below to get your BMI instantly and see whether you are underweight, at a healthy weight, overweight, or obese.
Free online BMI calculator: find your body mass index from height and weight, see your healthy weight range, and check it in metric or imperial units.
Example BMI-index calculations: METRIC UNITS
| BMI-index for 179 cm and 77 kg = 24.03 | BMI-index for 194 cm and 67 kg = 17.8 | BMI-index for 154 cm and 103 kg = 43.43 | BMI-index for 171 cm and 66 kg = 22.57 |
Example BMI-index calculations: US UNITS
| BMI-index for 5 ft 9 in and 201 lbs | BMI-index for 5 ft 8 in and 211 lbs | BMI-index for 5 ft 1 in and 240 lbs | BMI-index for 5 ft 2 in and 147 lbs |
5 things worth knowing about your body mass index (BMI) and the BMI Calculator
1. BMI is the abbreviation for body mass index.
2. In the last couple of decades, BMI was frequently criticized, although this index has been used since the middle of the 19th century. Mathematicians of the Oxford University claim that the formula distorts reality and it is worth using a factor of 1.3 for the calculation. It corrects the fact that the standard BMI index evaluates taller people to be thicker while shorter ones to be thinners.
3. The classic body mass index does not show your body fat percentage.
4. The general formula of BMI index is not applicable to children. In general, the formula gives a plausible result over the age of 20, while it strongly distorts reality under the age of 18.
5. The formula used for the calculation of your body mass index is as follows
How is BMI-index calculated?
| Measurement Units | Formula and Calculation |
|---|---|
| Kilograms and meters (or centimeters) | Formula: weight (kg) / [height (m)]2 With the metric system, the formula for BMI is weight in kilograms divided by height in meters squared. Because height is commonly measured in centimeters, divide height in centimeters by 100 to obtain height in meters. Example: Weight=68 kg, Height=165 cm (1.65 m) |
| Pounds and inches | Formula: weight (lb) / [height (in)]2 x 703 Calculate BMI by dividing weight in pounds (lbs) by height in inches (in) squared and multiplying by a conversion factor of 703. Example: Weight=150 lbs, Height=5’5″ (65″) |
Source: CBC - About adult BMI
Body mass index table (metric units, kg and cm) presented by BMI Calculator
How is BMI interpreted for adults?
For adults 20 years old and older, BMI is interpreted using standard weight status categories. These categories are the same for men and women of all body types and ages.
| Body mass index (kg/m²) | Weight category |
| < 16 | severly underweight |
| 16 – 16,99 | moderatly underweight |
| 17 – 18,49 | slightly underweight |
| 18,5 – 24,99 | normal weight |
| 25 – 29,99 | overweight |
| 30 – 34,99 | obese class I |
| 35 – 39,99 | obese class II |
| ≥ 40 | obese class III (severe) |
Body mass index table (inch and lbs)
6. Some opinions claim that the waist-to-hip ratio and its evaluation gives a much better picture of our health than BMI index.
7. If your body mass index is high, it is worth calculating your diabetes risk, as well.
Frequently asked questions
How is BMI calculated?
BMI is calculated by dividing your weight in kilograms by your height in metres squared (kg/m²). In imperial units, divide your weight in pounds by your height in inches squared and multiply by 703.
What is a healthy BMI?
For most adults a healthy BMI is between 18.5 and 24.9. Below 18.5 is underweight, 25 to 29.9 is overweight, and 30 or above is classed as obese.
Is BMI accurate for athletes?
BMI can overestimate body fat in very muscular people such as athletes, because muscle weighs more than fat. For them, measures like waist-to-hip ratio or body fat percentage give a clearer picture.
Does BMI work for children?
No. The standard BMI formula is meant for adults aged 20 and over. Children and teenagers should use age- and sex-specific BMI-for-age percentiles instead.
Is BMI the same for men and women?
The BMI formula and healthy range are the same for adult men and women. Body composition differs between the sexes, so BMI is a general screening tool rather than a direct measure of body fat.
What BMI is considered obese?
A BMI of 30 or higher is considered obese. It is further split into class I (30 to 34.9), class II (35 to 39.9), and class III (40 and above).