Health and Fitness Calculators
Understand common adult health estimates and plan your next run.
Health & Fitness tools
BMI Calculator
Calculate adult body mass index with metric or imperial measurements.
Health & FitnessCalorie Needs Calculator
Estimate adult maintenance energy needs from resting metabolism and activity.
Health & FitnessBMR Calculator
Compare adult resting-energy estimates from Mifflin–St Jeor and revised Harris–Benedict.
Health & FitnessBody Fat Estimate Calculator
Compare circumference and adult BMI-based body-fat estimates, including estimated fat and lean mass.
Health & FitnessRunning Pace Calculator
Calculate running pace, speed, or finish time from distance and duration.
Health & FitnessHeart Rate Zones Calculator
Estimate five exercise intensity zones using maximum heart rate or heart-rate reserve.
Health & FitnessWater Intake Calculator
Estimate daily total water from food and beverages using adult reference intakes, with activity context and optional fluid tracking.
Health & FitnessProtein Calculator
Estimate daily protein in grams from body weight, distinguishing the general adult reference from regular exercise and training ranges.
Health & FitnessPregnancy Calculator
Explore estimated conception timing and gestational age from your period, due date, conception date, ultrasound or IVF transfer.
Health & FitnessDue Date Calculator
Estimate when your baby is due using period dates, a supplied conception date, ultrasound gestational age or IVF transfer details.
Health & FitnessOvulation Calculator
Estimate ovulation, fertile-window dates and the next period from your cycle length, with optional cycle variation and a calendar.
Health & FitnessBlood Alcohol Content Calculator
Explore a rough educational BAC model using body weight, drink volumes, alcohol strengths and elapsed time, with explicit uncertainty.
Health & FitnessRecommended calculators
Understand the purpose and limits of each estimate
BMI relates weight to height, with separate adult ranges and a labeled CDC child/teen reference. BMR offers Mifflin–St Jeor, revised Harris–Benedict, and Katch–McArdle energy estimates; Calorie Needs adds activity assumptions. Running Pace solves distance, time, or pace. Heart Rate Zones uses a stated age formula or a maximum you enter.
Can these results replace a medical assessment?
No. These are screening and planning estimates. The BMI child/teen reference has its own age and sex inputs; other health models state their adult-use assumptions. Health, body composition, medication, and activity can change interpretation. Each page explains its limitations and relevant method references.