BMI Calculator
Calculate body mass index (BMI), view adult category ranges, and estimate healthy-BMI weight range for your height.
Above healthy BMI range. Additional risk depends on waist size and other factors.
Adult BMI Interpretation
BMI is a screening measure based on height and weight. Use with waist and body-composition context.
| RANGE | CATEGORY |
|---|---|
| 0-18.5 | Underweight Below standard BMI range for adults. Clinical context matters for interpretation. |
| 18.5-25 | Healthy Range Standard healthy BMI range for adults (18.5-24.9). |
| 25-30 | Overweight Above healthy BMI range. Additional risk depends on waist size and other factors. |
| 30-35 | Obesity Class I Higher BMI category with increased cardiometabolic risk in most populations. |
| 35-40 | Obesity Class II Substantially elevated BMI category. Clinical management is often recommended. |
| 40+ | Obesity Class III Highest standard BMI category. Medical follow-up is generally advised. |
What This BMI Calculator Shows
BMI is calculated as weight (kg) divided by height squared (m2). It is a quick screening metric used in public health and clinical workflows.
If You Searched for an Overweight Calculator
BMI is best for general screening. If your intent is planning around how much weight sits above the healthy range, use the BMI-based overweight calculator for a direct kg-above-threshold result.
A practical sequence is: screen with BMI, quantify current gap above healthy range, then map a timeline using the target-weight timeline calculator. For calorie targets behind that plan, run the TDEE Calculator and Calorie Deficit Calculator.
For height-focused planning and family-based context, use the Height Calculator and Height Estimator and Mid-Parental Height Calculator.
Limits of BMI
BMI does not directly measure fat, muscle, or fat distribution. Athletes and highly trained individuals can be misclassified despite low body fat.
For body-composition context, compare with a tape-based body fat estimate, waist-to-hip ratio risk check, waist-to-height ratio screen, waist-to-height roundness check, and height-normalized muscularity score (FFMI).
For a deeper breakdown, read our guide on when BMI helps and when body-fat percentage is more useful.
References
- CDC BMI calculation and interpretation:About Adult BMI
- CDC adult BMI categories:BMI Categories
More Weight Tools →
Weight Loss Percentage Calculator
Calculate percentage change from starting to current weight.
Overweight Calculator
Check BMI category and estimate weight above the healthy range.
Ideal Weight Calculator
Compare healthy BMI range and Devine ideal body weight.
Adjusted Body Weight Calculator
Calculate IBW, AdjBW, and percent-of-IBW for dosing context.