Health & fitness
calculators.

These health and fitness calculators provide common screening estimates in a format that makes the inputs and assumptions visible. Use BMI and body-fat tools for broad body-size or composition estimates, BMR for a baseline energy-use estimate, waist-to-height ratio for a simple proportion check, and target-heart-rate or VO2 max tools for exercise planning. They can help you track a trend or prepare a question for a clinician or coach.

The right tool depends on the measurement you actually have. BMI needs height and weight; BMR also uses factors such as age and sex; body-fat estimates depend on the selected method; and heart-rate or VO2 max results depend on age, resting heart rate, or a field test. These numbers are not diagnoses and may be less useful for children, pregnancy, athletes, or people with medical conditions. Discuss concerning results with a qualified professional. Use the same measurement method over time if your goal is to track a trend rather than compare yourself with a generic range.

Treat every result as a screening estimate, not a diagnosis. Measurement technique, age, medication, training status, body composition, and medical history can materially change interpretation.

Every tool is free, browser-based, and shows its formula, assumptions, and related calculators. Start with the closest match, then adjust the inputs to fit your situation.