Free BMI Calculator

Enter your height and weight to instantly calculate your BMI, see your category, and find your healthy weight range.

Calculate Your BMI

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Healthy Weight Range

What Is BMI?

Body Mass Index (BMI) is a simple screening metric that uses your height and weight to estimate body fat. It is calculated by dividing your weight in kilograms by the square of your height in meters. While BMI does not measure body fat directly, it correlates with more direct measures of body fat and is widely used by healthcare professionals as a first-pass assessment.

BMI Categories

BMI RangeCategory
Below 18.5Underweight
18.5 – 24.9Normal Weight
25.0 – 29.9Overweight
30.0 and aboveObese

Limitations of BMI

BMI does not distinguish between muscle mass and fat mass, so athletes with significant muscle may register as overweight despite having low body fat. It also does not account for bone density, age, gender, or fat distribution. For a more complete picture, consider combining BMI with waist circumference, body fat percentage, and other health indicators.

Despite these limitations, BMI remains one of the most accessible and widely studied tools for assessing weight-related health risks across large populations. It serves as an excellent starting point for conversations with your healthcare provider about weight management.

More Health Tools

Frequently Asked Questions

How is BMI calculated?
BMI is calculated by dividing your weight in kilograms by your height in meters squared (kg/m²). In imperial units, multiply weight in pounds by 703, then divide by height in inches squared.
What is a healthy BMI range?
A BMI between 18.5 and 24.9 is considered normal weight. Below 18.5 is underweight, 25–29.9 is overweight, and 30 or above is classified as obese.
Is BMI accurate for athletes?
BMI can overestimate body fat in athletes and people with significant muscle mass, since it does not differentiate between muscle and fat. Body fat percentage calculators provide a more accurate picture for athletic individuals.
Does BMI differ by age or gender?
Standard BMI categories are the same for adult men and women. However, women tend to have more body fat than men at the same BMI. For children and teens, BMI is age- and gender-specific using percentile charts.
How often should I check my BMI?
Checking your BMI once every few months is generally sufficient unless you are actively working on weight management. Pair it with other metrics like waist circumference for a more complete health picture.

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