Health & Medical Calculators
Evidence-based health calculators using established medical formulas. BMI, BMR, calorie needs, macro breakdowns, medication dosages, and more. These tools are for informational purposes only. Always consult a qualified healthcare provider for medical decisions.
- ✓Body composition: BMI, body fat, lean mass, ideal weight
- ✓Nutrition: calories, macros, protein intake, keto ratios
- ✓Medical: medication dosage, creatinine clearance, IV drip rates
- ✓Wellness: sleep cycles, caffeine intake, water needs
Most used: BMI Calculator, Calorie Calculator, Macro Calculator
Try any of the 38 health & medical calculators below — or get one free for your AI.
Every calculator on this page is free to use right now. You can also download any one as a Claude skill file (free with email) to chat with it in Claude Code, ChatGPT, or any AI platform. Or get the full Health & Wellness Pack for $29.
Common workflows in this category
Click any scenario to jump into the calculator with the example pre-loaded.
38 free calculators
A1C Calculator
Calculate average blood glucose from A1C percentage. Understand what your A1C result means for diabetes management and control.
Alcohol Unit Calculator
Calculate alcohol units from drinks and compare to recommended weekly limits. Track standard drink sizes and ABV.
Allergy Severity Calculator
Assess allergic reaction severity with our calculator. Understand symptoms and when to seek immediate medical help.
APGAR Score Calculator
Learn what your baby's APGAR score means. Interpret 1-minute and 5-minute scores and what they indicate.
Blood Alcohol Calculator
Calculate your estimated blood alcohol content. Know your BAC to make safe decisions about driving and impairment.
Blood Pressure Calculator
Interpret your blood pressure reading instantly. Know whether your BP is normal, elevated, or high, and what it means for your health.
Blood Type Compatibility Calculator
Discover which blood types are compatible with yours. Check donation and transfusion compatibility instantly.
BMI Calculator
Calculate your BMI in seconds. Understand what your body mass index means and whether you're at a healthy weight for your height.
BMR Calculator
Find how many calories your body burns at complete rest. Understand your baseline metabolism and how it fuels your daily life.
Body Fat Percentage Calculator
Calculate your body fat percentage using body measurements. Track your actual body composition, not just weight, to measure real progress.
Caffeine Calculator
Calculate safe caffeine intake based on your weight and see when caffeine leaves your system. Know your limit.
Calorie Calculator
Calculate how many calories you should eat daily to lose weight, gain muscle, or maintain. Personalized to your goals and activity level.
Carb Intake Calculator
Determine your ideal daily carbohydrate intake based on activity level and fitness goals. Optimize your macros for weight loss or performance.
Child Growth Percentile Calculator
Calculate growth percentiles for children's height and weight. Monitor if your child is growing within normal ranges using CDC standards.
Creatinine Clearance Calculator
Calculate creatinine clearance to evaluate kidney function using the Cockcroft-Gault equation. Crucial for medication dosing.
Drug Interaction Checker
Check for dangerous drug interactions before taking multiple medications. Identify mild, moderate, and severe interactions.
Fertile Window Calculator
Calculate your fertility window based on cycle length and ovulation date. Identify your 6 most fertile days each cycle.
Hearing Loss Calculator
Interpret your hearing loss degree from audiogram dB levels. Understand what mild, moderate, and severe hearing loss mean.
Heart Rate Zone Calculator
Calculate your optimal heart rate zones based on age and fitness level. Train smarter by hitting the right intensity zone.
Ideal Weight Calculator
Calculate your ideal weight based on height, age, and frame size. Get a personalized healthy weight range, not a single number.
Intermittent Fasting Calculator
Calculate intermittent fasting windows for 16:8, 18:6, 5:2, and other protocols. Plan your fasting and eating schedule today.
IV Drip Rate Calculator
Calculate IV drip rates in gtts/min and mL/hr. Essential tool for nurses, paramedics, and healthcare providers managing patient infusions.
Keto Calculator
Calculate exact macronutrient targets for the ketogenic diet. Determine your fat, protein, and carb ratios for success.
Lean Body Mass Calculator
Calculate your lean body mass to understand body composition. Determine how much of your weight is muscle, bone, and organs.
Life Expectancy Calculator
Calculate your estimated life expectancy using health, lifestyle, and demographic factors. Understand what impacts your longevity.
Macro Calculator
Find your ideal macronutrient split based on your goal. Calculate grams of protein, carbs, and fat you need daily for weight loss, muscle gain, or maintenance.
Medication Dosage Calculator
Calculate correct medication doses based on body weight. Essential for patients and healthcare providers. Ensure safe, accurate dosing.
Pediatric Dosage Calculator
Calculate correct medication dose for children by weight. Ensure safe and effective dosing for your child's medication.
Period Calculator
Calculate your next period date based on cycle length. Track menstrual patterns and identify irregularities easily.
Protein Intake Calculator
Calculate how much protein you need daily for your fitness goals. Adjust by age, weight, and activity level for optimal results.
Sleep Calculator
Calculate ideal bedtimes to wake up refreshed. Plan sleep based on 90-minute cycles for maximum rest and minimal grogginess.
Smoking Cost Calculator
Calculate total smoking costs and lost investment growth. See how much money cigarettes really cost over a lifetime.
SPF Calculator
Calculate your safe sun exposure time based on SPF level and skin type. Prevent sunburn with accurate protection estimates.
TDEE Calculator
Find your TDEE based on your metabolism and activity level. Know exactly how many calories you burn daily to plan your nutrition strategy.
Vaccine Schedule Calculator
Track your child's vaccination milestones with our vaccine schedule calculator. Know exactly when their next shot is due.
Vision Prescription Calculator
Understand what your eyeglass prescription numbers mean. Learn sphere, cylinder, axis, and pupillary distance explained.
Waist-to-Hip Ratio Calculator
Calculate your waist-to-hip ratio to evaluate health risk. Determine if your weight distribution indicates cardiovascular disease risk.
Water Intake Calculator
Calculate your daily water needs based on body weight, activity level, and climate. Stay hydrated with a personalized water goal.