Body Mass Index (BMI) is a quick estimate of whether your weight is in a healthy range for your height. This calculator works in both metric and imperial units.
Your numbers are processed in your browser and never uploaded. BMI is a general guide and not a medical diagnosis.
How to use the BMI Calculator
- Choose metric or imperial units.
- Enter your height and weight.
- See your BMI and the category it falls in.
How BMI is calculated
Body Mass Index is weight in kilograms divided by height in metres squared. Someone 1.75 m tall weighing 70 kg has a BMI of 70 divided by 3.0625, which is 22.9. The calculator accepts metric and imperial units and does the conversion for you.
What the ranges mean
| BMI | Category |
|---|---|
| Below 18.5 | Underweight |
| 18.5 to 24.9 | Normal weight |
| 25.0 to 29.9 | Overweight |
| 30.0 and above | Obesity |
BMI is a screening number, not a diagnosis. It does not distinguish muscle from fat, so athletes often score high while carrying little fat, and it reads differently across ages and body types. Treat it as one indicator among several, and talk to a doctor for a real assessment of healthy weight for your body.
Common uses
- A quick baseline check of weight relative to height
- Tracking direction of change over months
- Forms and screenings that ask for BMI
Embed this tool on your website
Copy this code into your blog or website to give your readers a working BMI Calculator, free. Please keep the credit link.
Frequently asked questions
Is the BMI calculator free?
Yes, free with no signup.
Is my data uploaded?
No. The calculation runs in your browser.
Does it work in pounds and inches?
Yes. Switch to imperial to use pounds and inches.
Is BMI a medical diagnosis?
No. BMI is a general guide; speak to a professional for personal health advice.