Calculate BMI
BMI calculator 
To calculate your BMI,
enter your height and weight in the form below,
either metric or imperial.
| Height | Weight BMI | Calculate BMI |
|---|---|---|
BMI table
BMI values according to WHO.
| BMI range | Weight category |
|---|---|
| Underweight | |
| -15.99 | Severe thinness |
| 16.00-16.99 | Moderate thinness |
| 17.00-18.49 | Mild thinness |
| 18.50-24.99 | Normal weight |
| 25.00-29.99 | Overweight |
| 30.00-34.99 | Obese - class I |
| 35.00-39.99 | Obese - class II |
| 40- | Obese - class III |
What is BMI?
BMI means Body Mass Index. The BMI shows the relation between a person's height and weight, and can be used to indicate whether the person has a normal weight or if he/she is underweight or overweight. BMI can also be called the Quetelet index, after its inventor, the Belgian scientist Adolphe Quetelet (1796-1874).
It is important to note that BMI is not actually a measurement for the percentage of body fat, and is not applicable to everybody (e.g. persons with a large muscle mass or bodybuilders).
For children and teenagers BMI is calculated the same way, but the thresholds for overweight, normal weight and underweight depends on the age and gender of the child. The BMI table that is being used for adults is not applicable to children and teenagers.
How to calculate Body Mass Index
Mathematically, BMI is kg/m2 (kilograms per square meter).
BMI formula
BMI calculation example
Example: A person is 175 cm tall and has a weight of 70 kg.
How to calculate BMI with imperial units: feet
To use pounds (lb) and feet (ft) instead of kilograms (kg) and meters (m), use the same fomula, but multiply the weight by 4.88.
BMI formula for pounds and feet
BMI calculation example (feet)
Example: A person is 5'6" tall and has a weight of 160 lb.
5'6" = 5 + (6/12) = 5.5'
Why the factor 4.88?
1 lb = 0.45359237 kg
1 ft = 0.3048 m
Where w is the weight in pounds, and h is the height in feet.
How to calculate BMI with imperial units: inches
To use pounds (lb) and inches (in) instead of kilograms (kg) and meters (m), multiply the weight by 703.
BMI formula for pounds and inches
BMI calculation example (inches)
Example: A person is 5'6" tall and has a weight of 100 lb.
5'6" = (5*12) + 6 = 60 + 6 = 66"
Why the factor 703?
1 lb = 0.45359237 kg
1 in = 0.0254 m
Where w is the weight in pounds, and h is the height in inches.
BMI Prime
BMI Prime is the BMI relative to the upper limit for normal weight. I.e. when the BMI is at the upper limit for normal weight, BMI Prime is 1.00. A BMI Prime value larger than 1.00 indicates overweight. For normal weight (BMI 18.5 - 25) the value of BMI Prime is between 0.74 and 1.00.
For Asian body types, BMI Prime should be between 0.80 and 1.00 (BMI 18.5 - 23 for normal weight). Please note that there may be differences in which BMI is considered to be the upper limit for normal weight.
BMI Prime formula
The formula to calculate BMI Prime is very simple:
BMI Prime formula for Asian body types
Since the upper limit for normal weight is often lower for Asian body types, the formula for BMI Prime looks like this:
Please note that there may be differences in which BMI is considered to be the upper limit for normal weight.
How to lose weight?
In theory it is simple to lose weight. Use more energy than you take in (eat).
However, in practice it is not so simple as it may sound, since it requires a lot of self control and hard work. But do not give up! If you really put your mind to it, you can do it. A good start could be to have a nice walk for at least 30-60 minutes every day. If you think it is boring, you could listen to music or audio books while walking, or walk with a friend.
If you start working out more than you are used to, you should consult your doctor first.