FREE BMI & WELLNESS CALCULATOR

BMI Calculator for Everyday Health Insights.

Calculate your Body Mass Index using height and weight. Choose metric or US measurements, view your BMI result instantly, and understand standard adult weight categories with a clear explanation of what BMI can and cannot tell you.

Age helps us display the right guidance: standard adult categories are intended for people age 20 and older. No signup or personal data upload is required.

✓ Instant BMI results✓ Metric & US units✓ Age-aware guidance✓ Copy your result

INTERACTIVE BMI CALCULATOR

Calculate Your Body Mass Index

Enter your age, height, and weight to see your BMI in real time. Adult BMI categories and the standard healthy BMI weight range appear for ages 20 and above.

BMI is a screening measure, not a diagnosis. It does not directly measure body fat, muscle mass, or an individual's overall health.

WHAT THIS TOOL SHOWS

Simple Numbers, Clearer Context

See the calculation and its limitations rather than relying on a single number without explanation.

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Your BMI Value

See your Body Mass Index based on height and weight, with an immediate result for either measurement system.

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Adult BMI Category

For adults age 20 and older, compare the result with standard BMI screening categories and their boundaries.

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Reference Weight Range

View the weight interval corresponding to adult BMI values of 18.5 up to, but not including, 25 for your height.

THREE EASY STEPS

How to Use the BMI Calculator

Enter your information and review an age-appropriate interpretation.

Enter Your Age

Age determines whether standard adult BMI categories apply. For children and teens, BMI-for-age assessment is needed.

Choose Units & Measurements

Use centimeters and kilograms, or switch to feet, inches, and pounds. Your units can be changed without re-entering values.

Review Your BMI

See the calculated BMI and, for adults, the standard category and reference weight range.

UNDERSTANDING THE RESULT

Standard Adult BMI Categories

For adults age 20 and older, these are commonly used screening ranges.

BMI Range	Adult Category	What It Means
Below 18.5	Underweight	Below the standard healthy BMI range.
18.5 to below 25	Healthy weight	Within the standard adult healthy BMI range.
25 to below 30	Overweight	Above the standard adult healthy BMI range.
30 or higher	Obesity	In the adult obesity BMI category; an individual assessment may be appropriate.

These adult categories do not apply to people younger than 20. They also do not replace professional evaluation of body composition, health history, or pregnancy-related changes.

HOW THE MATH WORKS

BMI Formula: Metric and US Units

BMI is calculated by dividing weight in kilograms by height in meters squared. The same result can be calculated with pounds and inches by multiplying by 703.

Metric: BMI = weight (kg) ÷ [height (m)]².

US: BMI = 703 × weight (lb) ÷ [height (in)]².

A person who is 170 cm tall and weighs 65 kg has a BMI of approximately 22.5. That is an example, not a personalized recommendation.

GOOD TO KNOW

BMI Is a Starting Point, Not a Diagnosis

BMI does not differentiate fat from lean muscle or account for all differences in body composition. Two people with the same BMI can have different health profiles.

Age, pregnancy, fitness level, health history, and other factors can affect how useful the result is. If a result raises concerns, discuss it with a qualified healthcare professional rather than relying on BMI alone.

QUESTIONS ANSWERED

BMI Calculator FAQs

Understand BMI calculations, age considerations, and common interpretation questions.

Why does this calculator ask for age?

It uses age to choose the appropriate guidance. Standard fixed adult BMI categories apply to people age 20 and older. Those younger than 20 require age- and sex-specific BMI-for-age interpretation.

Does age change the BMI formula?

No. The mathematical BMI value uses only height and weight. Age changes how that value should be interpreted, especially for children and teens.

Can a teenager calculate BMI here?

Yes, a numerical BMI can be calculated, but this page intentionally does not assign adult categories to users under 20. A pediatric BMI-for-age assessment also needs sex and precise age.

What is considered a healthy BMI for adults?

Under common adult screening categories, a BMI from 18.5 up to but not including 25 is classified as healthy weight. It is not a guarantee of health or an individualized goal.

How do I calculate BMI using pounds and feet?

Convert feet and extra inches into total inches, then calculate 703 × weight in pounds ÷ total inches squared. This calculator performs the conversion for you.

Is BMI accurate for muscular athletes?

BMI cannot distinguish muscle from fat. People with greater muscle mass may have a higher BMI without having the same body composition as someone else with the same BMI.

Should BMI be used during pregnancy?

BMI calculated from current pregnancy weight may not be an appropriate standalone interpretation. Seek guidance tailored to pregnancy and pre-pregnancy BMI from a qualified clinician.

Does the healthy BMI weight range mean my ideal weight?

No. The displayed range is derived from population-level adult BMI thresholds. It does not identify an ideal weight for an individual person.

Are the BMI calculations free and private?

Yes. Calculations run in your browser and do not require an account or a form submission. As with any website, its general hosting and analytics policies may still apply.

KEEP IT SIMPLE

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