BMI calculator
Your body mass index, its category and the healthy weight range for your height.
- 100% free
- No sign-up
- Runs in your browser
How to use BMI calculator
- Pick your units
- Enter height and weight
- Read your result
Your height and weight
Your BMI
Enter your height and weight to see your BMI.
WHO adult BMI categories
| Underweight | below 18.5 |
|---|---|
| Healthy weight | 18.5 – 24.9 |
| Overweight | 25 – 29.9 |
| Obesity class I | 30 – 34.9 |
| Obesity class II | 35 – 39.9 |
| Obesity class III | 40 or more |
BMI doesn’t measure body fat: muscular people can score high, and older adults low. It isn’t for children, teenagers or pregnancy, and some groups, including people of Asian heritage, may have higher risk at lower BMIs.
Next: Body fat calculator · Calorie calculator · Water intake calculator
Report a problem with this tool
How to use BMI calculator
Pick your units
Choose metric (cm and kg) or imperial (feet, inches and pounds). The choice is remembered for next time.
Enter height and weight
Type your height and your weight. The result updates as you type, with no button to press.
Read your result
See your BMI to one decimal, its WHO category on a coloured scale, and the weight range that counts as healthy at your height.
Why use Utils365
Metric or imperial
Use centimetres and kilograms, or feet, inches and pounds. Switching converts what you’ve typed.
Healthy range for your height
Not just a number: see the weights that give a BMI of 18.5 to 24.9, and roughly how far you are from them.
Honest about its limits
BMI is a quick screening number. The page says plainly who it doesn’t suit and what it can’t tell you.
Private
Worked out in your browser. Your height and weight aren’t sent or stored anywhere.
Frequently asked questions
How is BMI calculated?
Divide your weight in kilograms by your height in metres squared. At 70 kg and 1.75 m that’s 70 ÷ (1.75 × 1.75) = 22.9. In pounds and inches, multiply weight by 703 and divide by height in inches squared.
What is a healthy BMI?
For adults the WHO uses 18.5 to 24.9 as a healthy weight. Under 18.5 is underweight, 25 to 29.9 overweight, and 30 or more obesity, split into classes I (30–34.9), II (35–39.9) and III (40+).
What is a healthy weight for my height?
Multiply your height in metres squared by 18.5 and by 24.9. At 1.75 m that’s about 56.7 kg to 76.3 kg (125 to 168 lb). The calculator shows this range for your height.
Is BMI accurate?
It’s a rough guide for groups of people. It can’t tell muscle from fat, so athletes may show as overweight, and it misses where fat sits. Waist size and body fat percentage add to the picture.
Can I use it for children or during pregnancy?
No. Children and teenagers need BMI-for-age percentile charts, and weight gain in pregnancy is judged differently. This calculator is for adults aged 18 and over.
Is the healthy range different for Asian people?
Some health bodies suggest lower cut-offs for people of South Asian, Chinese and other Asian heritage, for example 23 for overweight and 27.5 for obesity, because risk rises at lower BMIs.
Why does my BMI say overweight when I’m fit?
Muscle is denser than fat, so muscular people often score 25 or more without carrying much fat. A body fat measurement is a better check in that case.