BMI Calculator

Calculate your Body Mass Index (BMI) using your height and weight. See your adult BMI category and understand what your result means.

For adults • Metric & Imperial units

Your BMI22.9Healthy weightStandard adult BMI range: 18.5–24.9
Underweight
Healthy
Overweight
Obesity

What Your Result Means

Your BMI of 22.9 falls within the standard healthy-weight BMI range for adults (18.5–24.9).

BMI is a screening measure based on height and weight. It does not directly measure body fat or determine your overall health.

BMI-Defined Weight Range for Your Height

Height: 175 cm · Corresponding weight range: approximately 56.7–76.3 kg

This is the weight interval corresponding to the standard adult BMI range for the height entered. It is not an individual target weight or medical recommendation.

This BMI calculator estimates Body Mass Index from your height and weight and places the result into one of the standard adult BMI categories used for screening purposes. It supports both a metric BMI calculator mode (kilograms and centimeters) and an imperial BMI calculator mode (pounds and inches), so you can calculate BMI for height and weight in whichever units you have on hand.

BMI is a screening measure, not a diagnosis - the sections below explain what a BMI category does and doesn't tell you.

Adult BMI Categories

BMICategory
Below 18.5Underweight
18.5–24.9Healthy weight
25.0–29.9Overweight
30.0–34.9Obesity Class 1
35.0–39.9Obesity Class 2
40 or higherObesity Class 3

These ranges are a screening reference, not a diagnosis.

Understanding BMI

BMI compares a person's weight with their height to provide a standardized screening number. That number is compared with established adult BMI ranges to give additional context about weight relative to height.

BMI Is a Screening Tool, Not a Diagnosis

BMI uses:

HeightWeight

But it does not directly measure:

Body-fat percentageMuscle massFat distributionBone massFitness levelOverall health

Two people with the same BMI can have very different body compositions, which is why BMI should be considered alongside other health information.

When BMI May Be Less Informative

Muscular People

Higher muscle mass may increase body weight without representing the same amount of body fat.

Pregnancy

Standard adult BMI interpretation is not intended to assess changes in body weight during pregnancy.

Children and Teenagers

Adult BMI categories should not be directly applied to children and teenagers. Their BMI is interpreted using age- and sex-specific measures.

Individual Differences

Body composition, age, fat distribution, and some population-specific factors may affect how meaningful BMI is when used by itself.

BMI Doesn't Tell the Whole Story

BMI can be useful as one screening measurement, but other measurements may provide additional context.

Body Fat Percentage

Estimates how much of total body weight comes from fat.

Body Fat Calculator
Waist Circumference

Can provide additional information about abdominal fat distribution.

Weight Trends

Changes over time can provide more context than a single measurement.

Common BMI Mistakes

Using Adult BMI for Children

Children and teenagers require age-specific interpretation.

Treating BMI as Body-Fat Percentage

BMI does not directly measure body fat.

Treating BMI as a Diagnosis

BMI is a screening measurement.

Ignoring Body Composition

Muscle mass can significantly affect body weight.

Looking for One "Perfect" BMI

BMI is interpreted using ranges rather than one universally perfect number.

Entering Incorrect Units

Make sure Metric and Imperial inputs match the selected calculator mode.

How to Use the BMI Calculator

  1. Choose Metric or Imperial units.
  2. Enter your current weight.
  3. Enter your height.
  4. Select Calculate BMI.
  5. Review your BMI number and BMI category.
  6. Use the supporting information on the page to understand what the result does and does not mean.

Frequently Asked Questions

What is BMI?

BMI, or Body Mass Index, is a screening number calculated from height and weight. It's used to place adults into general weight categories for reference, not to diagnose a medical condition.

What is considered a healthy BMI for adults?

For most adults, a BMI between 18.5 and 24.9 falls within the standard healthy-weight range. Below 18.5 is classified as underweight, and 25 or above falls into the overweight or obesity categories.

Does BMI directly measure body fat?

No. BMI is calculated from height and weight only - it does not directly measure body fat, muscle mass, or fat distribution.

Is BMI different for men and women?

The standard adult BMI categories use the same ranges for men and women. Body composition can still differ between individuals at the same BMI, which is one of its known limitations.

Can BMI be inaccurate for athletes or muscular people?

BMI can place muscular or highly trained individuals in a higher category than their body fat level would suggest, since it cannot distinguish muscle weight from fat weight.

Can children use this BMI calculator?

This calculator uses adult BMI categories, which are not intended for children or teenagers. Their BMI is interpreted using age- and sex-specific measures instead.

Can BMI be used during pregnancy?

Standard adult BMI interpretation is not intended to assess body weight changes during pregnancy.

Why can two people with the same BMI look different?

BMI does not account for how weight is distributed between muscle, fat, and bone. Two people with an identical BMI can have very different body compositions.

Is BMI the only measure of healthy weight?

No. BMI is one screening measurement among several. Body fat percentage, waist circumference, and weight trends over time can all add useful context.

What should I do if my BMI is outside the standard range?

BMI alone does not determine your health. If you have concerns about your weight or health, consider discussing your result with a qualified healthcare professional.

Last updated: September 29, 2026.