BMI Calculator
Find your Body Mass Index, see where you sit on the healthy scale, and check the ideal weight range for your height.
Your Stats
Enter your weight and height to see your BMI and healthy weight range.
What Is BMI?
BMI stands for Body Mass Index. It is a single number that compares your weight to your height. The formula is your weight in kilograms divided by your height in meters squared.
BMI was designed in the 1800s as a quick way to study population health. Today it is still used by doctors and insurers as a fast screening tool. It is not a perfect measure of individual health, but it is a useful starting point for most adults.
- • Underweight: below 18.5
- • Normal: 18.5 to 24.9
- • Overweight: 25 to 29.9
- • Obese: 30 and above
How We Calculate Your BMI
The math is simple, and the result lands you in one of four standard categories used around the world.
Convert Units
Weight goes into kilograms, height into meters. We handle that for you in both metric and imperial.
Apply the Formula
BMI equals weight in kilograms divided by height in meters squared.
Read the Category
We show your BMI, the category it falls in, and the healthy weight range for your height.
Factors BMI Does Not Capture
BMI only knows your height and weight. These are the variables it cannot see, and they matter when reading the result.
Muscle Mass
Muscle weighs more than fat by volume. Athletes and lifters often score in the overweight range despite being lean.
Frame and Bone Density
A wider frame or denser bones can push BMI up by a point or two without any extra fat or muscle.
Age
Adults lose muscle and gain fat as they age. Two people at the same BMI but 30 years apart usually have very different body compositions.
Ethnicity
BMI cutoffs were set in European populations. Risk thresholds shift up or down for South Asian, East Asian, and Black populations.
Sex
Women carry more essential body fat than men at the same BMI. The number alone cannot tell you the difference.
Body Fat Distribution
Belly fat is more harmful than fat carried on hips and thighs. Two people at the same BMI can face very different health risks.
Tips For Reading Your BMI The Right Way
- 1
Use It as a Screening Tool
BMI is a starting point, not a verdict. If you fall outside the normal range, look at body fat, waist, and lifestyle before drawing conclusions.
- 2
Pair It with a Waist Measurement
Waist under 94 cm for men and under 80 cm for women is the standard low risk threshold, regardless of BMI.
- 3
Track Lean and Fat Mass Separately
When you start training and eating more protein, your weight may not move much but your body fat percentage drops. BMI alone misses that.
- 4
Aim for the Healthy Weight Range
Targeting the middle of the normal BMI range is a sensible long term goal for most people. You do not need to chase a single perfect number.
- 5
Recheck Quarterly
BMI is most useful as a trend. Check every 2 to 3 months alongside how your clothes fit and how you feel in training.
- 6
Talk to a Professional
If your BMI flags a concern, a doctor or registered dietitian can put it in context with blood work, family history, and your goals.
BMI Calculator FAQ
Quick answers to the questions people ask most.