Health & Biohacking
Precise, science-backed metrics for training, nutrition, and long-term body composition goals.
Body Composition
8BMI Tracker
Body mass index, category, and a healthy weight range.
Open calculatorBody Fat Percentage Calculator
Estimate body fat percentage from tape measurements using the U.S. Navy method.
Open calculatorBody Adiposity Index (BAI) Calculator
Estimate body fat percentage from hip circumference and height alone — no scale needed.
Open calculatorLean Body Mass Calculator
Estimate lean mass and fat mass from height and weight using the Boer formula.
Open calculatorIdeal Body Weight Calculator
A reference weight from height using the Devine formula, with a healthy range.
Open calculatorWaist-to-Hip Ratio Calculator
A WHO-standard screening measure for body fat distribution and health risk.
Open calculatorWaist-to-Height Ratio Calculator
A simple, age- and sex-independent marker of cardiometabolic health risk.
Open calculatorWaist Circumference Health Risk Calculator
Classify your waist circumference against WHO cardiometabolic risk thresholds.
Open calculatorCalorie & Macro Planning
7Calorie Deficit Calculator
Your daily calorie target for a safe rate of fat loss.
Open calculatorTDEE Calculator
Total daily energy expenditure across every goal.
Open calculatorMacro Split Planner
Turn a calorie target into grams of protein, carbs, and fat.
Open calculatorWater Intake Calculator
How much water to drink daily based on weight, activity, and climate.
Open calculatorProtein Intake Calculator
Daily protein target in grams based on your weight and activity goal.
Open calculatorBMR Calculator
Basal Metabolic Rate — the calories your body burns at complete rest.
Open calculatorKatch-McArdle BMR Calculator
BMR from lean body mass — often more accurate for lean or muscular people.
Open calculatorPregnancy & Family
5Pregnancy Due Date Calculator
Estimate a due date from the last menstrual period or conception date.
Open calculatorConception Date Calculator
Estimate when conception likely occurred from a due date or last menstrual period.
Open calculatorChild Height Predictor
A child's likely adult height from both parents' heights, using the mid-parental height method.
Open calculatorOvulation Calculator
Estimate your ovulation day, fertile window, and next period.
Open calculatorPregnancy Weight Gain Calculator
Recommended total pregnancy weight gain for your pre-pregnancy BMI, per IOM guidelines.
Open calculatorEveryday Health
2Fitness & Training
9One-Rep Max Calculator
Estimate your one-rep max and training weights at every percentage.
Open calculatorHeart Rate Zone Calculator
Find your training zones using the Karvonen heart rate reserve method.
Open calculatorHeart Rate Recovery Calculator
Your 1-minute post-exercise heart rate recovery against the standard clinical benchmark.
Open calculatorSweat Rate Calculator
Your sweat rate during exercise from pre/post-exercise weight and fluid intake.
Open calculatorCalories Burned Calculator
Calories burned across 15 common activities, based on your weight and duration.
Open calculatorRunning Pace Calculator
Pace per mile and per km, speed, and predicted 5K, 10K, half, and marathon times.
Open calculatorSteps to Distance Calculator
Convert step count to walking distance using your height and stride length.
Open calculatorVO2 Max Calculator
Estimate your VO2 max from the Cooper 12-minute run test.
Open calculatorWeekly Exercise Guideline Calculator
See how your weekly exercise compares to the WHO physical activity guideline.
Open calculatorSleep & Recovery
5Sleep Cycle Calculator
Find the best bedtime or wake-up time based on 90-minute sleep cycles.
Open calculatorSleep Efficiency Calculator
Actual sleep time as a percentage of time in bed — the standard sleep-medicine metric.
Open calculatorCaffeine Half-Life Calculator
See how much caffeine is still in your system over time.
Open calculatorHow Much Sleep Do You Need?
National Sleep Foundation recommended sleep duration by age.
Open calculatorSleep Debt Calculator
Your accumulated sleep debt from target vs. actual sleep over a tracked period.
Open calculatorMedical Reference
5Blood Pressure Category Calculator
Classify a reading using the AHA/ACC guideline categories, from Normal to Hypertensive Crisis.
Open calculatorBlood Alcohol Content (BAC) Calculator
Estimate blood alcohol content from drinks, body weight, and time using the Widmark formula.
Open calculatorBlood Type Compatibility Calculator
Which blood types you can donate red blood cells to and receive them from.
Open calculatorA1C to Average Glucose (eAG) Converter
Convert A1C percentage to estimated average glucose in mg/dL and mmol/L, ADA formula.
Open calculatorBody Surface Area Calculator
Estimate your body surface area using the Mosteller formula.
Open calculatorDaily Nutrient Targets
13Daily Added Sugar Limit Calculator
American Heart Association recommended daily limit for added sugar, by sex.
Open calculatorDaily Iron Intake Calculator
NIH-recommended daily iron intake by age, sex, and pregnancy status.
Open calculatorDaily Magnesium Intake Calculator
NIH-recommended daily magnesium intake by age, sex, and pregnancy status.
Open calculatorDaily Zinc Intake Calculator
NIH-recommended daily zinc intake by age, sex, and pregnancy or breastfeeding status.
Open calculatorDaily Sodium Intake Calculator
See how your estimated sodium intake compares to CDC/AHA limits.
Open calculatorDaily Fiber Intake Calculator
Recommended daily fiber intake by age and sex, per Institute of Medicine guidelines.
Open calculatorDaily Vitamin D Intake Calculator
NIH-recommended daily vitamin D intake by age, in IU and mcg.
Open calculatorDaily Vitamin C Intake Calculator
NIH-recommended daily vitamin C intake by age, sex, and smoking status.
Open calculatorDaily Vitamin B12 Intake Calculator
NIH-recommended daily vitamin B12 intake by age and pregnancy or breastfeeding status.
Open calculatorDaily Folate (Folic Acid) Intake Calculator
NIH-recommended daily folate intake in mcg DFE, by age and pregnancy or breastfeeding status.
Open calculatorDaily Selenium Intake Calculator
NIH-recommended daily selenium intake by age and pregnancy or breastfeeding status.
Open calculatorDaily Calcium Intake Calculator
Recommended daily calcium intake by age and sex, based on NIH RDA guidelines.
Open calculatorDaily Potassium Intake Calculator
NIH-recommended daily potassium intake by sex.
Open calculator