What BMI means
BMI compares weight with height to estimate whether an adult is in a general weight category. It is a screening tool, not a diagnosis.
Adult body mass index tool
BMI Calculator
Calculate your body mass index in seconds with a private, easy-to-use BMI calculator for adults. Switch between metric and imperial units, then use the result as a starting point for a practical health conversation.
Calculate BMI nowFree BMI calculator online
Choose your units, enter your height and weight, and get an instant BMI result.
Healthy range
A BMI between 18.5 and 24.9 is commonly considered the healthy adult range, but personal context always matters.
Use context
Muscle mass, pregnancy, age, ethnicity, and medical history can affect what your number means for you.
Visual BMI guide
BMI levels for men and women
These simple BMI graphics show how the standard adult categories progress from underweight to obesity. They are illustrations for quick understanding, not a medical diagnosis or body-shape rule.
Men BMI level graphics
Man
Underweight
BMI below 18.5
A slim figure represents a BMI result below the usual adult healthy range.
Man
Healthy range
BMI 18.5-24.9
A balanced figure shows the common healthy adult BMI range.
Man
Overweight
BMI 25.0-29.9
A broader figure helps identify the overweight BMI range for adults.
Man
Obesity
BMI 30.0 or higher
The widest figure represents the highest standard adult BMI category.
Women BMI level graphics
Woman
Underweight
BMI below 18.5
A slim figure represents a BMI result below the usual adult healthy range.
Woman
Healthy range
BMI 18.5-24.9
A balanced figure shows the common healthy adult BMI range.
Woman
Overweight
BMI 25.0-29.9
A broader figure helps identify the overweight BMI range for adults.
Woman
Obesity
BMI 30.0 or higher
The widest figure represents the highest standard adult BMI category.
BMI guides for women and men
BMI Calculator for Adults
A BMI calculator is a quick way to estimate body mass index from your height and weight. This free BMI calculator online works in centimetres, metres, feet and inches, kilograms, or pounds, so you can use the measurements you already know. Enter your details above to receive a BMI score, an adult category, and an estimated healthy weight range for your height. No account is required, and your calculation runs in your browser.
BMI is calculated by dividing weight in kilograms by height in metres squared: weight / (height x height). For example, someone who weighs 70 kg and is 1.75 m tall has a BMI of about 22.9. The calculator converts imperial measurements before applying the same formula, so pounds and inches produce the same type of result as kilograms and centimetres.
For most adults, a BMI below 18.5 is classified as underweight, 18.5 to 24.9 as the healthy range, 25.0 to 29.9 as overweight, and 30.0 or higher as obesity. These categories are screening thresholds, not a complete picture of health. Your result is best understood alongside your waist measurement, activity, nutrition, medical history, sleep, and how you feel day to day.
People often search for a BMI calculator for women, BMI calculator for men, or a female BMI calculator and male BMI calculator. The adult BMI formula is the same for women and men, and this tool does not change your score based on the guide you select. The women and men options simply take you to additional context that may be relevant to different bodies and life stages. Pregnancy, menopause, muscle mass, age, and health conditions can all affect how a BMI result should be interpreted.
This website can also be used as a bmi calculator women guide, bmi calculator men guide, bmi calculator female resource, and bmi calculator male resource because the calculator is paired with separate adult education pages. Those pages explain why the same score may need different context depending on your body, goals, and medical background. The main calculator stays simple so you can get a clear number first, then read the guide that fits your needs.
A BMI check can be useful as a starting point for a conversation about weight and health, to track a broad change over time, or to understand general screening guidance. It should not be used to diagnose illness or judge your appearance. Athletes and people with higher muscle mass may have a higher BMI without having excess body fat. Older adults, growing teenagers, and people who are pregnant need more specialised guidance. If you are concerned about your weight, sudden changes, or symptoms, speak with a qualified healthcare professional.
This BMI calculator is designed to be clear and practical. You can switch between metric and imperial units, correct an entry, and calculate again without submitting personal information. We do not ask for your name, email address, or account. Use the result as one piece of information, set realistic goals, and focus on sustainable habits such as balanced meals, regular movement, enough sleep, and support from your healthcare team when you need it.
For the most useful result, measure height without shoes and use a recent weight from the same type of scale each time. If you track BMI over several months, look for broad patterns instead of reacting to a single reading. Normal daily changes in hydration, clothing, meals, and exercise can move body weight slightly, even when your longer-term health direction has not changed.
How to use the BMI calculator online
Start by selecting the measurement system that matches your height and weight. If you know your height in centimetres, choose cm. If you prefer feet and inches, choose ft + in. Then select kg or lb for weight, enter your current number, and press Calculate BMI. The result panel shows your BMI score, the broad adult category, and the healthy weight range for your entered height.
BMI calculator for women and men
You can use this as a BMI calculator for women, BMI calculator for men, male BMI calculator, or female BMI calculator because the calculation itself is based on adult height and weight. The extra women and men guides are there to help you interpret the score with more care. For example, body composition, hormone changes, pregnancy, training style, and age can all influence the usefulness of BMI as a health marker.
Frequently asked questions
Is this a BMI calculator for adults? Yes. The ranges shown are intended for adults. BMI interpretation for children and teenagers uses age- and sex-specific growth charts.
Can I use this as a male BMI calculator or female BMI calculator? Yes. Select Man or Woman for a relevant guide, while remembering that the score itself uses your height and weight only.
Is my BMI result a diagnosis? No. BMI is a screening measure and cannot measure body-fat distribution or overall fitness. Discuss questions about your result with a healthcare professional.