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Health & Fitness Calculators

Take charge of your wellness with our 39 free health and fitness calculators. From tracking body metrics and nutrition to monitoring pregnancy milestones, optimizing fitness training, and assessing medical health indicators, these evidence-based tools give you instant, personalized insights with no signup required.

Body Metrics

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Nutrition & Diet

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Pregnancy & Fertility

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Fitness

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Medical & Other

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About Health & Fitness Calculators

Understanding your body's metrics is the foundation of any effective health and fitness plan. Our health calculators translate complex medical formulas into clear, actionable numbers you can use every day.

The Body Metrics category includes 12 calculators covering BMI, body fat percentage, ideal weight, lean body mass, body surface area, and more. These tools use WHO-endorsed formulas and clinically validated equations to help you understand your body composition from multiple angles.

Our Nutrition & Diet calculators provide 10 tools for calorie counting, macronutrient planning, and hydration tracking. The calorie and TDEE calculators use the Mifflin-St Jeor equation, while specialized tools for protein, carbohydrate, and fat intake help you fine-tune your diet for specific goals.

The Pregnancy & Fertility section offers 9 calculators for due date estimation, ovulation tracking, period prediction, and pregnancy weight gain monitoring. These tools use Naegele's rule and IOM guidelines to support expectant and planning parents.

Our Fitness calculators help athletes and active individuals calculate running pace, one-rep max for strength training, and target heart rate zones using the Karvonen formula. The Medical category covers kidney function (GFR), blood alcohol content, sleep cycle optimization, life expectancy estimation, and smoking cost analysis.

All health calculators on this page are designed for educational and informational purposes. They rely on peer-reviewed formulas and guidelines from organizations such as the CDC, WHO, and NIH. However, they are not a substitute for professional medical advice. Always consult your healthcare provider before making changes to your diet, exercise routine, or health plan.

Frequently Asked Questions

Are these health calculators medically accurate?

Our calculators use peer-reviewed formulas from recognized health organizations including the WHO, CDC, and NIH. While they provide reliable estimates, individual results can vary based on factors like muscle mass, genetics, and medical conditions. Always discuss results with your healthcare provider.

Can I use the BMI calculator for children?

The standard BMI calculator on this page is designed for adults aged 20 and older. BMI assessment for children and teens requires age- and sex-specific percentile charts. Consult your pediatrician for an accurate child BMI evaluation.

How accurate is the pregnancy due date calculation?

The pregnancy calculator estimates your due date based on the first day of your last menstrual period using Naegele's rule, the same method most obstetricians use initially. Ultrasound dating, typically performed in the first trimester, provides a more precise estimate.

Should I follow the calorie calculator results exactly?

The calorie calculator provides a science-based starting point. Your actual needs may differ based on metabolism, medical conditions, medications, and daily activity variations. Use the results as a guideline and adjust based on how your body responds over two to four weeks.

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