Health Calculators
Last updated: September 2026
BMR / TDEE Calculator
Estimate your daily calorie needs using the revised Harris-Benedict equation, then adjust for activity to get your Total Daily Energy Expenditure (TDEE) — the rough number of calories you burn in 24 hours when you eat a maintenance diet.
Sleep Cycle & Wake Time Calculator
Work backward from your desired wake time to find the ideal bedtime based on your age and sleep quality factors.
BMR & Daily Calorie Needs Calculator
Calculate Basal Metabolic Rate (BMR) using the Mifflin-St Jeor equation, then multiply by an activity factor to estimate Total Daily Energy Expenditure (TDEE) — the calories you burn in a typical day.
BMI Calculator
Calculate Body Mass Index (BMI) — body weight in kg divided by height in metres squared — to screen for under/overweight categories.
Body Fat Percentage Calculator
Estimate your body fat percentage from a tape measure using the US Navy circumference method — the same protocol the US military uses for fitness compliance.
Calories Burned Calculator
Estimate calories burned during exercise from body weight, activity intensity (METs), and duration.
Heart Rate Training Zones Calculator
Calculate your personalised heart rate training zones using the Karvonen heart rate reserve method, which factors in resting heart rate to give zones that actually reflect your cardiovascular fitness.
Sleep Schedule Calculator
Find the bedtime that gives you enough actual sleep for your age group and goal, allowing for the time you spend awake in bed.
Macro Calculator
Split your daily calorie target into grams of protein, carbohydrates, and fat tuned to your goal — fat loss, muscle gain, or maintenance.
Lean Body Mass Calculator
Estimate your lean body mass — everything except fat — from height, weight, and sex using the Boer formula.
Blood Pressure Risk Assessment Calculator
Assess your cardiovascular risk score based on blood pressure readings, age, smoking status, and family history of heart disease.
Blood Alcohol Content (BAC) Calculator
Estimates your blood alcohol content (BAC) as a percentage from drinks consumed, body weight, sex and time since the first drink, using the Widmark formula.
BMI & Body Fat Percentage Calculator
Calculate your BMI and estimate body fat percentage from body measurements using the U.S.
Body Fat Calculator (Navy Method)
Estimates body fat percentage using the U.S.
Pregnancy Due Date Calculator
Estimate your due date and current pregnancy week from how many days ago your last menstrual period started, your average cycle length, and the dating method.
Blood Pressure Category Calculator
Classify blood pressure readings into clinical categories (normal, elevated, Stage 1 hypertension, Stage 2 hypertension, hypertensive crisis) based on systolic and diastolic values.
Waist-to-Hip Ratio Calculator
Divides your waist circumference by your hip circumference to gauge how body fat is distributed — a strong, simple predictor of cardiometabolic risk.
Pregnancy Due Date & Week Calculator
Calculates your estimated due date, current pregnancy week, and trimester from your last menstrual period or conception date.
Daily Water Intake Calculator
Estimate the daily water intake (in liters) a person should target based on body weight and physical activity level.
Mean Arterial Pressure (MAP) Calculator
Calculate your mean arterial pressure (MAP) from your systolic and diastolic readings.
Bra Size Calculator
Estimate a US bra size from underbust and bust measurements.
Body Type Calculator
Classify the female body shape (hourglass, pear, apple, or rectangle) from bust, waist, and hip measurements.
Heart Rate Zone Calculator
Calculate your personalised heart rate training zones using the Karvonen heart rate reserve method, which factors in resting heart rate to give zones that actually reflect your cardiovascular fitness.
Ideal Weight Calculator
Estimate your ideal body weight in pounds using four established medical formulas adjusted for height, gender, and body frame size.
Daily Protein Calculator
Calculate daily protein intake target in grams based on your body weight, activity level multiplier, and goal multiplier.
Macro Split Calculator
Determine how many grams of protein, carbohydrates, and fat to eat daily based on your calorie target, body weight, and fitness goal.
Calorie Deficit Weight Loss Calculator
Find your daily calorie target to lose weight by a specific date.
Body Surface Area Calculator
Calculate body surface area (BSA) in m² using the Mosteller, Du Bois or Haycock formula from your weight and height.