What is BMI?
BMI stands for Body Mass Index. It is a calculated measure of body weight relative to height and is commonly used as a simple adult weight category screening measure.
BMI - Body Mass Index - Adults 20+
Free BMI Calculator - Check Body Mass Index & Healthy Weight Range
Use this BMI calculator to estimate your Body Mass Index using metric units or US units. Instantly view your BMI number, adult BMI category, healthy weight range and easy interpretation.
BMI Calculator
Enter your height and weight to calculate BMI.
Your BMI
24.2
Healthy Weight
Your BMI result will appear here.
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BMI Formula
BMI = weight (kg) / height (m)2. For US units, the calculator converts pounds, feet and inches into the same BMI calculation.
Important Note
BMI is a screening tool, not a diagnosis. It should be considered with other health factors and professional medical advice when needed.
BMI Chart
Adult BMI Categories
Use this table to understand the adult BMI category shown by the calculator.
| BMI Range | Category | Quick Meaning |
|---|---|---|
| Below 18.5 | Underweight | Below the common adult reference range for height. |
| 18.5 to less than 25 | Healthy Weight | Within the common adult healthy BMI range. |
| 25 to less than 30 | Overweight | Above the common healthy BMI range. |
| 30 to less than 35 | Obesity Class 1 | First adult obesity class used for screening. |
| 35 to less than 40 | Obesity Class 2 | Second adult obesity class used for screening. |
| 40 or greater | Obesity Class 3 | Highest adult obesity class used for screening. |
How to use this BMI calculator
- Select Metric or US Units.
- Enter your height and weight.
- Click Calculate BMI.
- Review BMI value, category and healthy weight range.
BMI limitations
- BMI does not directly measure body fat.
- High muscle mass can affect interpretation.
- Age, medical history, activity level and waist measurement can add context.
- For personal health decisions, speak with a qualified healthcare professional.
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Medical disclaimer: This calculator is for general educational use. BMI is a screening measure and is not intended to diagnose disease or replace professional medical advice.
FAQ
BMI Calculator FAQs
What is BMI?
BMI is Body Mass Index, a calculated measure of body weight relative to height.
How do I calculate BMI manually?
Use the formula BMI = weight in kilograms divided by height in meters squared.
What is a healthy BMI?
For adults, BMI from 18.5 to less than 25 is commonly categorized as healthy weight.
Is BMI accurate for everyone?
BMI is a useful screening measure, but it does not directly measure body fat and may not reflect individual body composition.
Can I use this BMI calculator for children?
This page is designed for adults aged 20 and older. Children and teens need age and sex specific BMI percentiles.
What units does this BMI calculator support?
You can calculate BMI using centimeters and kilograms or feet, inches and pounds.
Does this page show healthy weight range?
Yes. After calculation, the tool estimates the weight range corresponding to adult healthy BMI values for the entered height.
Is this calculator free?
Yes. WisePro Toolbox calculators are free to use without registration.