Health & fitness calculators
Quick, well-sourced estimates for BMI, daily calories and running pace.
Screening estimates, explained
These calculators use widely published formulas — the BMI categories used by the CDC and WHO, the Mifflin-St Jeor equation for resting energy use, and simple distance-over-time math for pace. Each page shows the formula so you can see what the number does and does not tell you.
Health calculators give general estimates and are not medical advice. Talk to a doctor or registered dietitian before making changes to your diet, weight or exercise, especially if you have a medical condition, are pregnant, or are under 18.
Frequently asked questions
Is BMI accurate for everyone?
No. BMI is a quick screening number based only on height and weight. It does not measure body fat directly and can misclassify athletes, older adults and some ethnic groups.