Free calculators based on WHO, CDC and NIH guidelines

71 Health Calculators

From BMI to pregnancy tracking, nutrition planning to fitness goals - all the health calculators you need in one place.

71
Health Calculators
14
Health Categories
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Based on scientific research and medical standards

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Use {count}+ free online health calculators: BMI, daily calorie needs, pregnancy due date, body fat percentage, macro tracker and more. Get instant science-backed results — no signup, 100% free!

Body & Weight

Free BMI, ideal weight, body fat percentage, lean body mass and waist-hip ratio calculators. Track your body composition with science-backed tools.

10 tools

Fitness & Exercise

Calculate calories burned, one-rep max, running pace, VO2 max and daily step goals. Free fitness calculators for your workout planning.

5 tools

Nutrition & Diet

Free calorie, macro, protein, TDEE and BMR calculators. Plan your meals, track calorie deficit and reach your nutrition goals with accurate tools.

13 tools

Pregnancy & Birth

Calculate your due date, track pregnancy week by week, estimate fetal weight and predict baby gender. Free pregnancy calculators for expecting mothers.

6 tools

Women's Health

Track your menstrual cycle, calculate ovulation days and monitor fertility windows. Free tools for hormonal health and reproductive planning.

3 tools

Men's Health

Free PSA risk calculator and men's health screening tools. Monitor prostate health indicators and key fitness metrics with science-backed calculators.

1 tools

Heart & Cardiovascular

Calculate target heart rate zones, check blood pressure ranges and assess cholesterol levels. Free cardiovascular health calculators for heart monitoring.

5 tools

Diabetes & Blood Sugar

Convert HbA1c to average blood sugar, track glucose levels and manage diabetes with free online calculators. Instant, accurate results.

3 tools

Medical Calculations

Calculate GFR, creatinine clearance, body surface area and life expectancy. Free clinical calculators based on validated medical formulas.

4 tools

Mental Health

Screen for depression (PHQ-9), anxiety (GAD-7) and measure stress levels. Free, confidential mental health assessment tools with instant results.

3 tools

Sleep & Rest

Find your ideal bedtime, calculate sleep cycles, track sleep debt and optimize rest quality. Free sleep calculators for better sleep hygiene.

3 tools

Children's Health

Track child growth percentiles and predict adult height using WHO-standard charts. Free pediatric health calculators for parents and caregivers.

2 tools

Daily Life

Calculate your exact age, find your blood type compatibility, check pet age in human years and discover fun health insights. Free everyday tools.

9 tools

Substance & Alcohol

Calculate blood alcohol content (BAC), track caffeine intake, count alcohol calories and plan smoking cessation. Free substance awareness tools.

4 tools
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What you get on ProHealthCalc

71+ calculators across 14 health categories — BMI, daily calorie needs (TDEE), body fat, due date, ovulation, A1C, GFR, PHQ-9, and more. Each one runs in your browser, returns a result in under a second, and shows the formula and the source it came from (WHO, CDC, NIH, AHA, peer-reviewed studies).

Each calculator page includes the formula in plain language, an example calculation, what the result means, when it does not apply (athletes, pregnancy, elderly, ethnic-specific cut-offs), and links to the original guidelines. We do not collect what you type — calculations happen on your device, no account, no tracking of inputs.

These tools are for self-education. They are not a substitute for a doctor, a diagnosis, or a treatment plan. If a result concerns you, talk to a clinician who can see your full history.