Fitness and health calculators
Quick estimates based on published formulas, with the formula and its limits explained. They are a starting point, not a diagnosis.
- BMI calculator
Body mass index and the healthy weight range for your height.
- Calorie calculator
Calories a day to maintain, lose or gain weight.
- Body fat calculator
Body fat percentage from a few tape measurements.
Which health calculator do you need?
Start with the BMI calculator for a quick screening measure that compares your weight with your height, using the CDC’s adult categories. It also shows the weight range that counts as healthy for your height.
Use the body fat calculator when you want a better picture of your build than BMI gives. With a tape measure and a few minutes, it estimates body fat using the method the US Navy developed.
Use the calorie calculator to find out roughly how much energy your body uses each day, and what a slow, steady change up or down would look like.
Good to know
- These calculators use published formulas designed for healthy adults.
- Results are a starting point for a conversation with your doctor, not a diagnosis.
- Track trends over weeks rather than reacting to a single number.
Every calculation is exact for the numbers you enter and shows its working. Read how we check our formulas.