Health & Fitness
Free health calculators for BMI, BMR, body fat, calories, macros, heart rate zones, and water intake.
76 free tools available
Browse in-depth health & fitness guides
A1C Calculator
Convert average blood glucose to A1C percentage and vice versa.
Alcohol Calorie Calculator
Estimate calories from beer, wine, spirits, and cocktails.
Baby Growth Percentile Calculator
Estimate baby weight and length percentile based on WHO growth data.
BAC Calculator
Estimate blood alcohol content based on drinks, body weight, gender, and time elapsed.
BAI Calculator
Calculate your Body Adiposity Index (BAI) using hip circumference and height.
Bench Press Calculator
Estimate your bench press one-rep max based on reps and weight.
Blood Pressure Calculator
Check your blood pressure category based on systolic and diastolic readings.
BMI Calculator
Calculate your Body Mass Index and see your weight category.
BMR Calculator
Calculate your Basal Metabolic Rate using the Mifflin-St Jeor equation.
Body Fat Calculator
Estimate body fat percentage using the U.S. Navy method.
Body Frame Calculator
Determine your body frame size from wrist circumference and height.
Body Surface Area Calculator
Calculate body surface area using the Mosteller formula for medication dosing and clinical use.
Bra Size Calculator
Estimate bra size from band and bust measurements.
Caffeine Calculator
Estimate total caffeine intake from coffee, tea, energy drinks, and more.
Caffeine Half-Life Calculator
Estimate how long caffeine stays in your bloodstream based on dose, half-life, and time elapsed.
Caffeine Limit Calculator
Estimate your maximum safe daily caffeine intake based on body weight.
Calcium Needs Calculator
Estimate daily calcium requirements based on age, gender, and pregnancy or lactation status.
Calorie Calculator
Estimate daily calorie needs based on activity level.
Calorie Deficit Calculator
Calculate the daily calorie deficit needed to reach your weight loss goal by a target date.
Calories Burned Calculator
Estimate calories burned from exercise based on activity, weight, and duration.
Carb Calculator
Calculate daily carbohydrate needs based on calories and diet goals.
Cholesterol Ratio Calculator
Calculate total-to-HDL and LDL-to-HDL cholesterol ratios.
Conception Calculator
Estimate conception date from due date or last menstrual period.
Due Date Calculator
Estimate pregnancy due date based on last menstrual period.
Fat Calculator
Calculate daily fat intake in grams based on calorie target and diet percentage.
Fertility Window Calculator
Estimate your most fertile days and next ovulation date based on cycle length.
Fiber Calculator
Calculate daily fiber needs based on age and gender.
GAD-7 Anxiety Screening
Score the GAD-7 questionnaire for anxiety severity. Not a diagnosis.
Heart Rate Zone Calculator
Calculate target heart rate zones for exercise.
Heart Rate Variability Calculator
Calculate RMSSD from a series of RR intervals in milliseconds.
Ideal Body Weight Calculator
Estimate ideal body weight using the Devine formula based on height and gender.
Ideal Weight Calculator
Estimate ideal weight range based on height using BMI.
Iron Needs Calculator
Estimate recommended daily iron intake based on age, gender, and pregnancy status.
Jet Lag Calculator
Estimate how long it takes to recover from jet lag based on time zones crossed.
Lean Body Mass Calculator
Estimate lean body mass using the Boer formula based on weight, height, and gender.
Macro Calculator
Calculate daily protein, carb, and fat targets.
Marathon Time Predictor
Estimate your marathon finishing time from a recent half-marathon or 10K result.
Max Heart Rate Calculator
Estimate your maximum heart rate using common formulas based on age.
Medication Dosage Calculator
Calculate medication dose based on body weight and prescribed mg/kg.
Metabolic Age Calculator
Estimate metabolic age from chronological age, weight, height, and estimated body composition.
Nap Calculator
Find the best nap duration and wake-up time to avoid grogginess.
Navy Body Fat Calculator
Estimate body fat percentage using the U.S. Navy circumference method.
One Rep Max Calculator
Estimate your one-rep max based on weight lifted and reps performed.
Ovulation Calculator
Predict ovulation and fertile window based on cycle length.
Ovulation Tracker
Track ovulation and fertile window across multiple cycles.
Pace Calculator
Calculate running pace per mile or kilometer from time and distance.
PHQ-9 Depression Screening
Score the PHQ-9 questionnaire for depression severity. Not a diagnosis.
Pregnancy Calculator
Track pregnancy week by week and estimate due date.
Pregnancy Week Calculator
Calculate current pregnancy week and trimester from last menstrual period.
Pregnancy Weight Gain Calculator
Estimate recommended weight gain during pregnancy based on pre-pregnancy BMI.
Protein Calculator
Calculate your daily protein needs based on weight, activity level, and goals.
Race Time Predictor
Predict race times for common distances based on a recent run performance.
Readiness Score Calculator
Estimate daily workout readiness from sleep, resting heart rate, and subjective recovery.
Recovery Heart Rate Calculator
Assess cardiovascular fitness by measuring how much your heart rate drops after exercise.
Relative Fat Mass Calculator
Estimate body fat percentage with the Relative Fat Mass (RFM) equation using height and waist.
RMR Calculator
Calculate resting metabolic rate — the calories your body burns at complete rest.
Skinfold Body Fat Calculator
Estimate body fat percentage using the Jackson-Pollock 3-site skinfold method.
Sleep Calculator
Find optimal bedtime or wake-up time based on sleep cycles.
Sleep Debt Calculator
Calculate accumulated sleep debt from insufficient sleep over multiple nights.
Sleep Efficiency Calculator
Measure sleep efficiency as the percentage of time in bed that is spent sleeping.
Sleep Schedule Calculator
Find optimal bedtime or wake-up time based on sleep cycles.
Smoking Cost Calculator
Calculate how much money you spend on cigarettes over days, months, and years.
Sodium Calculator
Track daily sodium intake against recommended limits.
SPF Calculator
Estimate how long sunscreen protects your skin based on SPF and skin type.
STOP-BANG Sleep Apnea Screening
Assess obstructive sleep apnea risk with the STOP-BANG questionnaire.
Sugar Calculator
Calculate recommended daily sugar intake limits and track added sugars.
Sunburn Time Calculator
Estimate how long you can stay in the sun before burning based on skin type and UV index.
Sweat Rate Calculator
Estimate your sweat rate during exercise to build a hydration plan.
TDEE Calculator
Calculate total daily energy expenditure based on activity level.
Training Stress Score Calculator
Estimate training stress score (TSS) from workout duration and intensity relative to threshold.
Vitamin D Calculator
Convert vitamin D between IU and micrograms (mcg) and estimate daily needs.
Vitamin D Needs Calculator
Estimate daily vitamin D needs based on age, weight, and sun exposure.
VO2 Max Calculator
Estimate VO2 max from running or walking performance using a simple formula.
Waist to Height Ratio Calculator
Calculate waist-to-height ratio and assess health risk category.
Waist-to-Hip Ratio Calculator
Calculate your waist-to-hip ratio and assess body fat distribution.
Water Intake Calculator
Calculate recommended daily water intake.