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Health Tool

BMI Calculator

Calculate body mass index instantly in metric or imperial units. Check your BMI category, estimated healthy weight range, and practical health notes with a clear visual chart.

cm
kg
yrs
Body mass index
0.0
Normal range

Enter your height and weight to see BMI, category, healthy range estimate, and simple guidance.

BMI chart
Underweight
< 18.5
Normal
18.5-24.9
Overweight
25-29.9
Obesity
30+
Healthy weight range

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Distance to normal

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Height used

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Weight used

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BMI overview BMI is a screening tool that compares weight with height. It helps estimate whether body weight is low, typical, high, or very high for a given height.
Ideal weight note The healthy weight estimate uses the standard BMI range of 18.5 to 24.9. It is a general guideline rather than a diagnosis.
Recent BMI checks
No saved entries yetYour last few calculations will appear here on this device.

How to Use the BMI Calculator

  • Select metric or imperial units depending on how you want to enter your measurements.
  • Enter your height and weight, then click calculate to get your BMI result instantly.
  • Review the BMI value, category, healthy weight range, and simple health guidance.
  • Use the recent history area to compare multiple checks stored locally in your browser.

What Is BMI?

Body Mass Index, or BMI, is a simple screening method that compares your weight with your height. It is widely used to group results into ranges such as underweight, normal, overweight, and obesity.

BMI formula explained

In metric units, BMI is calculated as weight in kilograms divided by height in meters squared. In imperial units, it is weight in pounds divided by height in inches squared, multiplied by 703. This tool handles both automatically.

Healthy BMI ranges

For most adults, a BMI below 18.5 is considered underweight, 18.5 to 24.9 is considered a healthy range, 25 to 29.9 is considered overweight, and 30 or above is categorized as obesity.

Limitations of BMI

BMI does not directly measure body fat, muscle mass, age-related changes, or overall health. Athletes, older adults, and people with different body compositions may need additional context beyond BMI alone.

Health tips

Use BMI as a quick screening tool, not a diagnosis. A balanced diet, regular activity, sleep, and guidance from a qualified health professional provide a better picture of long-term health than a single number.

Frequently Asked Questions

How do I calculate BMI?

Enter your height and weight.

Is this tool free?

Yes.

What is a healthy BMI?

Typically 18.5 to 24.9.

Can I use feet and inches?

Yes.