Fitness & Health

BMI Calculator

Calculate BMI, category, and a healthy-weight range from height and weight.

Inputs

Results update as you edit.

ft
in
lb

BMI

24.4

Results update as the calculator inputs change.

This calculator is informational and is not medical advice.

Category

Healthy weight

Healthy weight range

129-174 lb

Height in inches

70

How to Calculate BMI

Height and Weight
BMI uses body weight relative to height to create a screening number.
BMI Formula
For U.S. units, BMI equals 703 times weight in pounds divided by height in inches squared.
Category
The result is compared with standard adult BMI categories.

How to Interpret BMI

BMI is a screening measure, not a diagnosis. It can be useful for population-level and first-pass weight categories, but it does not directly measure body fat, muscle, or health status.

What Affects BMI Interpretation?

Height

Small height entry errors can noticeably change BMI.

Weight

BMI changes directly with body weight.

Muscle Mass

High muscle mass can raise BMI without indicating excess body fat.

Age and Sex

BMI interpretation can differ for children, teens, pregnancy, and older adults.

Health Markers

Blood pressure, labs, waist size, and medical history add important context.

Clinical Review

Use BMI as a starting point and ask a clinician for personal guidance.

Related Weight Measures

BMI Category

Compare the BMI result with common adult category ranges.

Healthy Range

Estimate the weight range that maps to healthy adult BMI for the entered height.

Waist and Fitness

Use waist circumference and fitness measures for added context.

Frequently Asked Questions

What does BMI measure?

BMI estimates weight relative to height. It does not directly measure body fat or diagnose health.

What BMI range is considered healthy for adults?

Common adult categories place healthy weight from BMI 18.5 to less than 25.

Can athletes have a high BMI?

Yes. More muscle mass can increase BMI even when body fat is not high.

Is BMI used for children?

Children and teens use age- and sex-specific BMI percentiles, not the adult categories shown here.

Should I make health decisions from BMI alone?

No. Use BMI as a screening tool and consider clinical advice, waist measurements, labs, and overall health.