A simple calculation
BMI = weight (kg) ÷ height (m)². For example, 70 kg at 1.75 m gives a BMI of 22.9.
Explore the formula ↗ A LITTLE CLARITY. A HEALTHIER PERSPECTIVE.BMI calculator.
BMI calculator.
Know your number.
See the bigger picture.
One simple check-in with yourself. Calculate your body mass index, understand the result, and keep track of changes over time.
↗ Instant results◇ No sign-up⌁ Private tracking
YOUR HEALTH IS MORE THAN A NUMBER
Balanceyouat the centerContext
A useful starting point.
A more informed next step.
01 / YOUR CHECK-IN
Adults 20+Let's find your BMI
Your measurements stay in this browser. No account needed.
02 / YOUR PERSPECTIVEReady when you are
—BODY MASS INDEX · kg/m²
A number. Not your whole story.
Enter your height and weight to see your result and what it means.
▼
UnderweightHealthy weightOverweightObesity
BMI is a screening tool, not a diagnosis.
Saving is optional. Your history is stored only on this device.
Simple by design. Thoughtful by nature.
Standard BMI formula · CDC adult categories · No registration
A LITTLE KNOWLEDGE GOES A LONG WAYUnderstand the number.
Understand the number.
Keep the context.
Body mass index compares weight with height. It can help start a health conversation, but it cannot tell the whole story.
A starting point
Use the result alongside your health history, waist measurement and a clinician's advice.
Read common questions ↗A pattern over time
Optional check-ins help you see changes. No score defines your health or your worth.
Visit your progress ↗THE ADULT BMI CHARTWhere does
Where does
your number fit?
These standard categories apply to adults aged 20 and older. The calculation and category thresholds are the same for men and women.
View CDC category guidance ↗UnderweightBelow 18.5
Healthy weight18.5 to <25
Overweight25 to <30
Obesity30 or above
Categories use the unrounded BMI. The displayed result is rounded to one decimal.
YOUR JOURNEY, AT YOUR PACE
◇ On-device onlySmall check-ins. A clearer picture.
Your story starts with one check-in.
Calculate your BMI, then choose “Save check-in” to start tracking.
Browser data can be cleared. Export a copy to keep your records.
GOOD QUESTIONS. CLEAR ANSWERS.A little more
A little more
understanding.
Here is what to know before making decisions based on your BMI.
Is BMI an accurate measure of health?
It is a useful screening measure, but cannot distinguish fat from muscle or show where fat is stored. A clinician can interpret it with other information.
Is BMI calculated differently for women and men?
No. The standard adult formula and category thresholds are the same. Personal health context can still differ.
Can children or teenagers use this calculator?
This tool is for adults 20 and older. Ages 2–19 need age- and sex-specific percentiles. Use the CDC child and teen calculator.
Should I use BMI during pregnancy?
This calculator does not interpret pregnancy weight. Ask your maternity care provider for guidance appropriate to your stage of pregnancy.
How is my information stored?
Calculations happen in your browser. History is saved only when you choose, using this site's browser storage. It is not synced across devices. Anyone using your browser profile may be able to see it. Delete history here or clear site data in your browser.
Why might my category look different from a rounded result?
We classify the full calculation before rounding. A value just below 25, for example, may display as 25.0 while remaining below the category boundary.
Transparent by design
Metric formula: kg ÷ m². US entries are converted using 1 inch = 0.0254 meters and 1 pound = 0.45359237 kilograms. No sex or age adjustment is added to adult BMI.
Reference: CDC Adult BMI Calculator and Adult BMI Categories. BMITrack is an independent tool and is not affiliated with the CDC. It does not provide a diagnosis or treatment plan. Discuss individual concerns with a qualified healthcare professional.
Check in with yourself.
Calculate my BMI ↗Free to use. No account. Just a little clarity.