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BMI Calculator
Quick answer
If weight is 70 kg and height is 170 cm, the BMI is 24.2.
BMI formula (body mass index): BMI = weight (kg) ÷ height (m)².
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BMI
24.2
Body Mass Index — weight relative to height, used as a rough screening figure rather than a precise health measure.
Normal
24.2
Normal
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About the BMI Calculator
Body mass index (BMI) compares your weight with your height to give a single number used to screen for underweight, healthy weight, overweight and obesity. Enter your weight in kilograms and your height in centimetres.
The World Health Organization groups adults as underweight below 18.5, healthy from 18.5 to 24.9, overweight from 25 to 29.9 and obese at 30 or more.
BMI formula (body mass index)
BMI = weight (kg) ÷ height (m)²
A person who is 70 kg and 170 cm (1.70 m) has a BMI of 70 ÷ 2.89 = 24.2.
Things to keep in mind
- BMI cannot tell muscle from fat, so athletes and older adults may be misclassified.
- Many Indian and Asia-Pacific guidelines use lower cut-offs — about 23 for overweight and 25 for obesity — because health risks begin at lower BMI in South Asian adults.
- BMI is a screening tool, not a diagnosis. Speak to a doctor about your weight and health.
See how the result changes
Each table re-runs this calculator with one value changed and everything else left as it is.
BMI by weight
If weight goes from 70 kg to 105 kg, BMI changes from 24.2 to 36.3 (+50%).
| Weight | BMI |
|---|---|
| 35 kg | 12.1 |
| 52.5 kg | 18.2 |
| 70 kgstart | 24.2 |
| 105 kg | 36.3 |
| 140 kg | 48.4 |
BMI by height
If height goes from 170 cm to 255 cm, BMI changes from 24.2 to 10.8 (−56%).
| Height | BMI |
|---|---|
| 85 cm | 96.9 |
| 128 cm | 42.7 |
| 170 cmstart | 24.2 |
| 255 cm | 10.8 |
| 340 cm | 6.1 |
HEALTH & FITNESS GUIDE
A quick guide to BMI
Use it to get an accurate BMI in seconds — free, with no sign-up.
Instant results
See your BMI the moment you enter your numbers.
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Accurate & transparent
The same standard formula runs on our server for every calculation.
How to Use the BMI Calculator
1
Enter Weight
Provide your weight, in kg.
2
Enter Height
Provide your height, in cm.
3
View Your Results
Get your BMI instantly, calculated on our server.
What is BMI?
This health & fitness tool works out your BMI instantly, so you don't have to do the math by hand.
“One quick calculation, so you always know your BMI before you decide.”
What Affects Your BMI
Your BMI depends on the values below.
Weight
Changing your weight changes your BMI.
Height
Changing your height changes your BMI.
Example Result
Here's what you can expect from a BMI calculation:
- Weight
- 70 kg
- Height
- 170 cm
- BMI
- 24.2
Frequently Asked Questions
- What is a healthy BMI for Indians?
- The WHO range is 18.5 to 24.9. For Asian adults, many guidelines treat 23 and above as overweight and 25 and above as obese, so a BMI of roughly 18.5 to 22.9 is considered lowest risk.
- Is BMI accurate?
- It is a quick screening number, not a full health check. It ignores muscle mass, body fat distribution, age and sex, so use it together with waist size and medical advice.
- How do I calculate my BMI?
- Divide your weight in kilograms by your height in metres squared. For example, 70 kg at 1.70 m gives 70 ÷ 2.89 = 24.2.
- How does weight affect BMI?
- If weight goes from 70 kg to 105 kg, BMI changes from 24.2 to 36.3 (+50%).
- How does height affect BMI?
- If height goes from 170 cm to 255 cm, BMI changes from 24.2 to 10.8 (−56%).
- How to calculate BMI?
- Fill in weight and height in the BMI Calculator above and your BMI is calculated instantly. Change any value to see how the result responds.
- What does an example BMI calculation look like?
- If weight is 70 kg and height is 170 cm, the BMI is 24.2.
- Is this calculator free to use?
- Yes — every calculator on this site is completely free, with no sign-up or account required.
- How accurate is this calculator?
- It uses the standard formula and calculates on our server for every request, so results are precise for the values you enter.
- Is my data saved anywhere?
- No. Nothing you enter is stored or sent anywhere unless you choose to share a link with your values included.
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