BMI Calculator
Calculate BMI from height and weight in seconds using metric or imperial units and review the general screening range.
Unit system
Metric mode uses centimetres and kilograms.
Enter height and weight, then calculate BMI.
BMI result
18.5 to 24.9
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BMI is a general screening estimate only. It does not diagnose health or body fat by itself.
Calculate BMI
Category guide
- < 18.5 Underweight
- 18.5 - 24.9 Normal
- 25.0 - 29.9 Overweight
- >= 30.0 Obese
Medical reminder
For health concerns or treatment decisions, consult a qualified health professional.
How to use
Follow these simple steps to use the tool.
Select metric (cm and kg) or imperial (ft, in, and lb).
Add your values in the selected units, then run the calculation.
See your BMI estimate and general range classification, then read the screening note.
What it does
See what this free online tool can help with.
Calculates BMI from height and weight using metric or imperial units.
Shows a quick category estimate such as underweight, normal, overweight, or obese.
Displays the healthy BMI range reference for adult screening context.
Works without requiring an account.
Supported formats and limits
Review supported inputs, outputs, and practical limits for this tool.
Formats and options
- Metric: centimetres and kilograms
- Imperial: feet, inches, and pounds
- BMI output with general category label
Things to know
- BMI is a general screening estimate, not a diagnosis.
- This tool does not account for muscle mass, age, pregnancy, or medical conditions.
- For medical advice or health decisions, speak with a qualified health professional.
FAQ
Answers to common questions about this tool.
What is BMI?
BMI stands for body mass index. It is a simple calculation based on height and weight that is often used as a general screening measure.
Is BMI a medical diagnosis?
No. BMI is only a rough screening tool. It does not measure body fat directly and does not account for muscle mass, age, pregnancy, ethnicity, fitness level, or overall health.
What units can I use?
The tool supports common metric and imperial inputs, such as centimetres and kilograms or feet, inches, and pounds.
Who should use a BMI calculator?
A BMI calculator can be useful for a quick general estimate. For medical advice, health concerns, or weight-related decisions, speak with a qualified health professional.
Why use a free online BMI calculator?
A free online BMI calculator is useful when you want a quick estimate without installing an app or building a spreadsheet.
Enter your height and weight, calculate instantly, and review the general category range in one place. It is designed for simple screening context, not for diagnosis or treatment decisions.