Free Health & Fitness Calculators
Evidence-based calculators for everyday health questions: body mass index, daily calorie needs, body fat estimate, ideal weight range, water intake, sleep timing and pregnancy due date.
These are general estimates for healthy adults, based on published formulas. They are not a diagnosis. Talk to a doctor or dietitian about your personal situation.
8 free tools · No sign-up · Works on phones and computers
All health tools
- BMI CalculatorPopularBody mass index in metric or imperial units, with the healthy range.
- Calorie Calculator (TDEE)PopularDaily calories to maintain, lose or gain weight, based on your activity.
- BMR CalculatorBasal metabolic rate: the calories your body burns at rest.
- Body Fat CalculatorEstimate body fat percentage with the U.S. Navy tape-measure method.
- Ideal Weight CalculatorHealthy weight range for your height, using four common formulas.
- Water Intake CalculatorA sensible daily water target based on weight, activity and climate.
- Sleep CalculatorBest times to go to bed or wake up, based on 90-minute sleep cycles.
- Pregnancy Due Date CalculatorEstimated due date and current week from your last period or conception date.
Health tools: common questions
Are these calculators medically accurate?
They use established formulas (for example Mifflin–St Jeor for calorie needs and the U.S. Navy method for body fat). Formulas give population-level estimates; individuals vary.
Is my health data stored?
No. Your height, weight and other details stay in your browser.
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