BMI Calculator - Body Mass Index & Healthy Weight Range
Calculate adult body mass index from height and weight, then compare the result with common BMI categories and an estimated healthy weight range.
Your Measurements
Enter your height and weight.
BMI Scale
Underweight
< 18.5
Normal
18.5 - 24.9
Overweight
25 - 29.9
Obese I
30 - 34.9
Obese II+
35+
Your BMI
Body Mass Index result.
Body Mass Index
23.6
Normal weightBMI is a screening tool, not a diagnostic measure. Consult a healthcare provider for personalised guidance.
Methodology and limitations
Last reviewed:
Methodology
Calculates adult BMI as weight (kg) ÷ height (m)² using standard WHO/CDC category thresholds for adults 20 and older.
Limitations
BMI does not measure body fat directly and may misclassify muscular or elderly individuals. Not intended for children, pregnant women, or clinical diagnosis.
Official sources
How to Calculate Adult BMI
Calculate adult body mass index from height and weight, then compare the result with common BMI categories and an estimated healthy weight range.
Method used
The calculator converts height and weight to metric units when needed, then calculates body mass index and compares it with common adult BMI categories.
BMI = weight in kilograms / (height in meters x height in meters)
Practical example
An adult who is 5 feet 9 inches tall and weighs 160 pounds has a BMI of about 23.6, which falls in the common healthy weight category.
- Height: 5 ft 9 in
- Weight: 160 lb
- Unit system: imperial
The result shows BMI, weight category, and an estimated healthy weight range for the entered height.
Assumptions
- The BMI categories are adult screening categories.
- Height and weight are user-entered measurements.
- BMI is an estimate and is not a medical diagnosis.
What this includes
- Imperial and metric inputs, BMI value, adult BMI category, and estimated healthy weight range.
What this excludes
- Child BMI percentiles, pregnancy, clinical diagnosis, body-fat measurement, muscle mass, ethnicity-specific risk, and medical history.
Related calculators
Frequently Asked Questions
What is BMI?
BMI, or body mass index, is a screening measure that compares weight with height. It can estimate weight category for many adults, but it is not a diagnosis.
What BMI range is usually considered healthy for adults?
The CDC adult BMI categories list 18.5 to 24.9 as the healthy weight range for most adults.
Is BMI accurate for everyone?
No. BMI does not directly measure body fat, muscle mass, pregnancy status, ethnicity-specific risk, or medical history. Use it as a screening estimate only.
Can athletes have a high BMI and still be healthy?
Yes. Muscle weighs more than fat, so very muscular people may fall into the overweight BMI range despite low body fat. A body composition assessment may be more informative.
Should I use BMI if I am pregnant?
Standard adult BMI is not designed for pregnancy. Pregnant individuals should follow prenatal weight guidance from their healthcare provider instead.