Health screening · US + metric
Know your BMI in seconds.
Enter your height and weight to see your body mass index, category and a healthy weight range. All calculation happens on your device.
Your measurements
Use US customary units or metric. Nothing leaves your browser.
Your BMI
25.1
Above the typical healthy range.
Healthy weight range
125-169 lb
Based on a BMI of 18.5 to 24.9 for your height. A clinician may set a different target for you.
How to read it
Useful context, not a verdict.
BMI compares your weight with the range typically associated with good health for your height. It is cheap, consistent and easy to compare, which is why clinicians and researchers still use it. It is also blunt.
- It does not show body fat, muscle mass or where fat is stored.
- Adult cut-offs do not apply to children, pregnancy or some ethnic groups in the same way.
- A single reading is less useful than the trend over time.
- Waist circumference and other measures can add context.
What does BMI actually measure?
BMI is a ratio of weight to height. It is a quick screening tool for weight status across groups of people, not a measure of body fat, fitness or health. It does not distinguish muscle from fat.
Which BMI categories does this calculator use?
It uses the standard adult cut-offs: under 18.5 is underweight, 18.5 to 24.9 is healthy weight, 25 to 29.9 is overweight, and 30 or above is obesity. These are general ranges for adults.
Can I use this calculator in pounds and feet?
Yes. Switch to US units to enter height in feet and inches and weight in pounds. Switch to metric to use centimeters and kilograms. The result is the same BMI.
Is BMI accurate for athletes or older adults?
Not always. Muscular athletes can have a high BMI without excess fat, while older adults can have a normal BMI with low muscle mass. Pregnancy, some medical conditions and certain medications also affect how useful BMI is.
Should children use this calculator?
No. Children and teenagers are assessed with age- and sex-specific BMI percentiles, not the adult cut-offs used here. Ask a pediatrician if you have concerns about a child's growth or weight.
Is this medical advice?
No. The BMI calculator is for general information only. It cannot diagnose a health condition or replace an assessment by a qualified clinician. Seek personalized advice for your circumstances.
Is my data stored?
No. The calculation runs in your browser. Your height and weight are not sent to simplytools.us or any third party, and nothing is saved after you close the page.