BMI Calculator
Calculate your Body Mass Index with visual results
🔒 100% free · no signup · files never leave your device
Body Mass Index is the screening metric used by the World Health Organization and most national health services to classify weight status cheaply and consistently across large populations. It divides weight in kilograms by the square of height in meters, and the WHO bands are well established: below 18.5 is underweight, 18.5–24.9 is the healthy range, 25–29.9 overweight, and 30 and above indicates obesity.
This free BMI calculator accepts metric or imperial units — no need to convert feet and pounds by hand — and returns your BMI instantly along with the category scale and your personal healthy weight range for your height. It is important to treat the result as a screening indicator, not a diagnosis: BMI cannot distinguish muscle from fat, so athletes often read 'overweight' despite low body fat, and it says nothing about fat distribution, which modern research links more strongly to health risk. Use it as a quick, free starting point and discuss concerns with a professional.
Why use BMI Calculator
Routine health self-check
A quick BMI reading every few months shows whether your weight is drifting outside the healthy band before it becomes a problem.
Setting realistic weight goals
The healthy weight range output translates the abstract BMI bands into concrete kilograms or pounds to aim for.
Preparing for a medical appointment
Many intake forms ask for BMI or height/weight stats — having the number ready speeds up the paperwork.
Tracking fitness program progress
Paired with waist measurement, BMI trends offer a simple longitudinal signal that a training or diet plan is working.
Pro tips
- Weigh yourself at a consistent time — morning, after the bathroom, before eating — for comparable readings; daily weight fluctuates 1–2 kg.
- Measure height without shoes, standing straight; people typically overestimate height by 1–2 cm, which skews BMI noticeably.
- If you're muscular, pair BMI with waist circumference (risk rises above ~102 cm men / 88 cm women) for a truer picture.
- BMI bands apply to adults; children and teens use age- and sex-specific percentile charts, and pregnancy makes BMI meaningless.
How to use BMI Calculator
- 1Enter height and weight (metric or imperial)
- 2See your BMI instantly
- 3Check the category scale and healthy range
Frequently Asked Questions
What is a healthy BMI?▾
According to WHO, a BMI between 18.5 and 24.9 is considered the healthy range for adults.
Is BMI accurate for athletes?▾
BMI doesn't distinguish muscle from fat, so muscular people may show as 'overweight'. It's a screening tool, not a diagnosis.