BMI Calculator
Calculate your BMI in metric or imperial units and see your category. Free and private, right in your browser.
BMI calculator (metric & imperial)
Calculate your Body Mass Index from height and weight in metric or imperial units, and see which WHO category you fall into: underweight, normal, overweight or obese. BMI is a general screening tool and does not account for muscle mass; consult a professional for medical advice.
What is a healthy BMI?
A BMI between 18.5 and 24.9 is generally considered a healthy weight range for most adults.
How to calculate your BMI
- Choose metric (kg, cm) or imperial (lb, ft) units.
- Enter your height and weight.
- Your BMI is calculated instantly in your browser.
- See which BMI category your result falls into.
How to Calculate BMI Quickly and Accurately
Body Mass Index (BMI) is a simple, widely used metric that helps you gauge whether you’re underweight, normal weight, overweight, or obese based on your height and weight.
Kwiklr offers a free, instant BMI calculator that does the math for you—just enter your numbers and see the result in seconds.
Why BMI Matters
BMI provides a quick snapshot of potential health risks related to body weight, making it a useful starting point for fitness planning, medical assessments, and nutrition advice.
How It Works
The formula is weight (kg) divided by height (m) squared: BMI = weight ÷ (height × height). If you use pounds and inches, the calculation is weight (lb) ÷ [height (in) × height (in)] × 703.
How to Calculate Your BMI
- Gather your weight in kilograms (or pounds).
- Measure your height in meters (or inches).
- Convert units if needed (1 lb = 0.453592 kg; 1 in = 0.0254 m).
- Plug the numbers into the formula: BMI = weight ÷ (height × height).
- Enter your values into Kwiklr’s BMI Calculator for an instant result.
Tips for Accurate Results
- Use a calibrated scale.
- Measure height without shoes.
- Record weight at the same time of day, preferably in the morning.
- Prefer metric units (kg, m) to avoid conversion errors.
Common Problems
People often mix units (pounds with meters) or round numbers too early, leading to inaccurate BMI values. Double‑check that both weight and height are in the same unit system before calculating.
Frequently asked questions
Can I calculate BMI in kg and cm?
Yes. Switch to metric and enter your height in centimetres and weight in kilograms.
What BMI category am I in?
The calculator shows whether your BMI falls in the underweight, normal, overweight or obese range.
Is my data uploaded?
No. The calculation runs in your browser, so your details stay private.
Is this medical advice?
No. BMI is a general guide only and does not replace advice from a healthcare professional.
What does a high BMI indicate?
A high BMI (typically over 25) suggests overweight or obesity, which can increase the risk of heart disease, diabetes, and other health issues.
Can BMI be used for athletes?
BMI doesn’t differentiate muscle from fat, so very muscular individuals may appear overweight despite low body fat.
Is BMI accurate for all ages?
BMI is a screening tool for adults; children and seniors may need age‑adjusted charts or alternative assessments.