BMI Calculator

Quickly calculate your Body Mass Index (BMI) to understand if you’re in a healthy weight range for your height.

What is BMI?

Body Mass Index (BMI) is a simple formula used to estimate a healthy body weight based on a person's height. It is calculated by dividing a person’s weight in kilograms by the square of their height in meters. BMI is a widely used screening tool to categorize underweight, normal weight, overweight, and obesity in adults.

How to calculate BMI

The formula for BMI is straightforward:

  • BMI = weight (kg) / [height (m)]²

For example, if you weigh 70 kg and are 1.75 m tall:

  • BMI = 70 / (1.75 × 1.75) = 22.86

What does your BMI mean?

According to the World Health Organization (WHO):

  • Underweight: BMI < 18.5
  • Normal weight: BMI 18.5 – 24.9
  • Overweight: BMI 25 – 29.9
  • Obese: BMI ≥ 30

Benefits of using a BMI calculator

Our online BMI calculator provides a fast and easy way to:

  • Understand if your weight is within a healthy range
  • Monitor changes over time
  • Support discussions with healthcare providers

Limitations of BMI

BMI does not differentiate between weight from fat and muscle. For instance, athletes with high muscle mass may be classified as overweight even if they have low body fat. It also doesn’t account for age, sex, or body composition differences. Always consult healthcare professionals for a comprehensive assessment.

Use cases

Our BMI calculator is useful for adults tracking their weight goals, fitness enthusiasts assessing their health status, or anyone curious about maintaining a healthy lifestyle.

Other useful calculators

Explore related tools on our site:

Maintaining a healthy BMI supports overall wellness and reduces the risk of chronic diseases. Use this tool regularly to stay informed about your health.

Frequently Asked Questions

What is BMI and how is it calculated?

BMI stands for Body Mass Index and is calculated by dividing your weight in kilograms by your height in meters squared. It provides a general indication of whether you’re underweight, normal weight, overweight, or obese.

Is BMI accurate for everyone?

BMI is a useful screening tool but not always accurate for individuals with high muscle mass, elderly people, or children. It does not differentiate between muscle and fat.

What is a healthy BMI range?

A BMI between 18.5 and 24.9 is considered healthy for most adults. Values outside this range may indicate underweight or overweight.

How often should I check my BMI?

You can check your BMI every few months or when you notice significant weight changes. It’s a helpful tool for tracking trends over time.

Does BMI account for muscle mass?

No, BMI does not distinguish between muscle and fat. Someone very muscular may have a high BMI but low body fat.

References

BMI Calculator interface to calculate body mass index online

Written by Creesler

Last updated: 6/29/2025