BMI Calculator - DigiKitApp

Calculate your body mass index from weight and height.

When should you use this?

Use this to get a general sense of body mass index based on height and weight.

When shouldn't you use this?

BMI can show a muscular body type (an athlete's, say) as higher than it really should be; this tool gives a general indicator, for a personal health assessment you should consult a doctor.

Step-by-step

Enter your current weight in Weight (kg). Weighing yourself in the morning before breakfast gives the most consistent readings.
Enter your height in Height (cm), in centimeters rather than meters, so 175 instead of 1.75.
Click Run. Your body mass index appears in the result area.
Compare the number with the general ranges below, and treat it as a starting point rather than a verdict on your health.

Example

BMI is weight in kilograms divided by height in meters squared. For someone who weighs 70 kg and is 175 cm tall, that's 70 divided by 1.75 times 1.75, which comes to about 22.9. The World Health Organization's adult categories are: below 18.5 underweight, 18.5 to 24.9 normal, 25 to 29.9 overweight, and 30 or above obese. This person falls in the normal range. At 80 kg, the same person would be at about 26.1, which is in the overweight range.

What is body mass index (BMI)?

BMI is found by dividing weight by the square of height: BMI = kg ÷ (height in metres)². The World Health Organization classification is: below 18.5 underweight, 18.5-24.9 normal, 25-29.9 overweight, 30 and above obese. For example 70 kg and 1.75 m gives 70 ÷ 3.0625 ≈ 22.9.

When interpreting BMI

BMI does not separate muscle from fat; muscular athletes can score high.
The same thresholds are not used for children, teenagers, pregnancy and older people.
Waist circumference and overall health also matter.
This tool is not medical advice or a diagnosis; if you are concerned, consult a health professional.

Things to keep in mind

These categories are for adults. For children and teenagers, BMI is read against growth charts by age and sex, and the adult ranges don't apply.
BMI doesn't show where fat is stored. Waist circumference adds useful information, especially about fat around the abdomen.
Weight is assessed differently during pregnancy and in older age. In those cases, talk to your doctor rather than interpreting the number yourself.
A noticeable change in weight over a short period is worth raising with a doctor, whatever range your BMI is in.

Frequently asked questions

How accurate are the results?

Calculations use standard mathematical formulas; for official purposes (tax, loan applications, etc.) we recommend confirming current rates with the relevant institution.

Are the numbers I enter saved?

No, no numbers are sent to a server; the calculation happens entirely in your browser.

Can I use this on mobile?

Yes, the tool works smoothly on all screen sizes.