Questions
Frequently asked questions
Answers about how the calculators work, what the results mean, and where the estimates have limits.
Frequently asked questions
What is BMI?
BMI is a calculated measure of body weight relative to height. For adults it is a screening measure, not a diagnosis.
What are adult BMI categories?
Underweight is below 18.5; healthy weight is 18.5 to less than 25; overweight is 25 to less than 30; obesity is 30 or greater.
Does BMI measure body fat?
No. BMI uses height and weight and does not directly measure body-fat percentage or fat distribution.
Can children use adult BMI categories?
No. Children and teens need age- and sex-specific BMI-for-age interpretation.
What is BMR?
BMR is an estimate of resting energy expenditure from a predictive equation.
What is TDEE?
TDEE is an estimate of total daily energy expenditure, commonly estimated by applying an activity factor to BMR.
Are calorie results exact?
No. They are estimates based on equations and generalized activity assumptions.
Why do ideal-weight formulas disagree?
They were developed from different data and assumptions and use different coefficients.
Is the body-fat calculator clinical?
No. It provides a circumference-based estimate and can be affected by measurement technique.
Are the calculators private?
The static calculators process entered values in the browser and do not require an account or a backend for calculation.
Can I use BMI during pregnancy?
Standard adult BMI calculations should not be used as a pregnancy health assessment.
Do the calculators diagnose disease?
No. The site is informational and does not diagnose or treat conditions.