Health & Body
Free Health & Body calculators with instant results, clear explanations and worked examples — no sign-up, available in 9 languages.
Estimate body measures like BMI, body-fat and ideal weight, daily calorie and hydration needs, heart-rate zones and pregnancy or ovulation dates. Use them to set a baseline or sanity-check a number before a workout or appointment — they are educational estimates, not a diagnosis, so confirm anything important with a clinician.
All Health & Body calculators
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BMI Calculator
Calculate your Body Mass Index and see where you land on the WHO healthy-weight range. Metric or imperial, instant, free, no sign-up.
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BMR Calculator
Calculate your basal metabolic rate using the Mifflin-St Jeor equation and preview daily calorie needs by activity level. Metric or imperial, free.
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Body Fat Calculator
Estimate your body-fat percentage with the U.S. Navy circumference method and see your fitness category. Metric or imperial, instant, free, no sign-up.
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Caffeine Half-Life Calculator
Estimate how much caffeine is left in your body at bedtime and when it drops below the level that disrupts sleep. Free, instant, no sign-up.
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Calorie Calculator
Calculate your daily calorie needs (TDEE) and a balanced macro split for losing, maintaining or gaining weight. Mifflin-St Jeor, metric or imperial, free.
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Daily Water Intake Calculator
Estimate a daily water target from your body weight, exercise, and climate. Shown as an easy range in litres and cups. Free, instant, no sign-up.
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Ideal Weight Calculator
Find your ideal body weight from four classic formulas plus the healthy BMI range for your height. Metric or imperial, instant, free, no sign-up.
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Mean Arterial Pressure (MAP) Calculator
Find mean arterial pressure, pulse pressure, and your blood-pressure category from a systolic/diastolic reading. ACC/AHA and ESC guidelines. Free, instant.
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Ovulation Calculator
Estimate your ovulation day and fertile window from your last period and cycle length, with your next three cycles projected. Free and instant.
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Pregnancy Due Date Calculator
Pregnancy due date calculator. Estimate from your last period, conception date, or IVF transfer — see gestational age and trimester on a 40-week timeline.
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Protein Target Calculator
Estimate a sensible daily protein range for your body weight and goal, plus how much to aim for per meal. Free, instant, no sign-up.
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Sleep Debt Calculator
Estimate the sleep debt you have built up from short nights and how many recovery nights it takes to pay it back. Free, instant, no sign-up.
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