health Calculators
BMI Calculator
Body Mass Index (BMI) is the most widely used screening tool for relating a person's weight to their height. It produces a single number that places adults into broad weight categories — underweight, healthy weight, overweight, or obese — and is used by the WHO, the CDC, and the NHS as a first-pass indicator of weight-related health risk. Enter your weight in kilograms and height in centimetres and the calculator returns your BMI in kg/m². The result is meant as a starting point for a conversation with a clinician, not a diagnosis on its own.
Calories Burned Calculator
Estimates the calories you burn during exercise based on your body weight, workout duration, and intensity level. Ideal for tracking energy expenditure across different activities.
Daily Water Intake Calculator
Estimate how much water you should drink each day based on body weight and activity level — a far better starting point than the generic "8 glasses a day" rule, which has no scientific basis. The output is total fluid in litres, including water from food (typically about 20% of daily intake) and beverages other than plain water.
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. Used by coaches and endurance athletes to keep aerobic, threshold, and VO2-max sessions in the right intensity bands.
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. Enter your waist, neck, height (and hip if female) and the calculator returns body fat percentage, accurate to within ±3–4 percentage points compared to a DEXA scan.
Blood Pressure Category Calculator
Classify your blood pressure reading into Normal, Elevated, Stage 1, or Stage 2 Hypertension using AHA guidelines. Use it after taking a reading at home or at the doctor's office.
Pregnancy Due Date Calculator
Estimate your baby's due date based on how many weeks pregnant you are. Useful at any point in pregnancy to quickly determine how many weeks remain until your estimated delivery date.
Ideal Weight Calculator
Estimate your "ideal" reference body weight from your height, biological sex, and body frame size using the Devine formula — originally created in 1974 for pharmacological dose calculation and still used clinically today. Useful as a rough planning anchor, but not a personal weight goal: it ignores muscle mass, age, and individual physiology.
Sleep Schedule Calculator
Find a bedtime that lets you wake up at the end of a complete 90-minute sleep cycle, minimising the groggy, disoriented feeling (sleep inertia) of being yanked out of deep sleep by an alarm. Enter your desired wake time and how many full cycles you want, and the calculator backs out the bedtime.
Daily Protein Calculator
Calculate your daily protein requirement in grams based on your body weight, activity level, and fitness goal. Use it when starting a diet, building muscle, or adjusting your nutrition plan.
BMR & Daily Calorie Needs Calculator
Find your Basal Metabolic Rate and total daily calorie needs using the Mifflin-St Jeor equation. Enter your weight, height, age, and activity level to get a personalized calorie target for weight loss, maintenance, or gain.
Macro Split Calculator
Break down your daily calorie target into grams of protein, carbohydrates, and fat based on your chosen macro percentages. Use this when starting a new diet plan, cutting, or bulking to hit precise nutrition targets.
BMI & Body Fat Percentage Calculator
Calculate your BMI and estimate body fat percentage from body measurements using the U.S. Navy circumference method. Useful for anyone who wants a more complete picture of body composition beyond simple weight.
Calorie Deficit & Weight Loss Calculator
Estimate how much weight you will lose over a set number of weeks by entering your maintenance calories, target intake, and exercise burn. Perfect for planning a structured fat-loss phase or evaluating whether a deficit is realistic.
Daily Water Intake Calculator
Find out how much water you should drink each day based on your body weight, exercise habits, climate, and special conditions like pregnancy. Use it to stay properly hydrated and avoid fatigue or dehydration.
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. Use this to wake up at the end of a sleep cycle feeling naturally refreshed.
Blood Pressure Risk Assessment Calculator
Estimate your cardiovascular risk score from systolic and diastolic blood pressure, age, gender, and lifestyle risk factors. Useful for a quick self-assessment before discussing results with a healthcare provider.
BMR & TDEE Calculator
Calculate your Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE) using the Mifflin–St Jeor equation. Essential for setting accurate calorie targets when losing, gaining, or maintaining weight.
Body Fat Percentage Calculator
Estimate your body fat percentage using the US Navy tape-measure method. Enter your height, waist, neck, and (for women) hip measurements to get an instant result without specialist equipment.
Macro Calculator
Split your daily calorie target into grams of protein, carbohydrates, and fat tuned to your goal — fat loss, muscle gain, maintenance, or keto. The output is the macro target sports-nutrition coaches and bodybuilders use to plan meals and track adherence with apps like MyFitnessPal or Cronometer.
Blood Pressure Category Calculator
Enter your systolic and diastolic readings to instantly find your blood pressure category and Mean Arterial Pressure (MAP). Useful for anyone monitoring hypertension or tracking cardiovascular health at home.
Pregnancy Due Date Calculator
Estimates your due date, current pregnancy week, and trimester from your last menstrual period or conception date. Useful for expectant parents tracking milestones from the first positive test.
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. Enter your weight in kilograms, height in centimetres, age, biological sex, and an activity multiplier (sedentary 1.2, lightly active 1.375, moderately active 1.55, very active 1.725, extremely active 1.9). The result is what most nutrition guides call your "maintenance calories" — a starting point for designing a deficit (to lose weight), a surplus (to gain muscle), or a recomposition plan.
Body Surface Area Calculator
Calculate your Body Surface Area (BSA) in m² using the Mosteller, Haycock, or DuBois formula. Clinicians and pharmacists use BSA to dose chemotherapy, renal drugs, and burn treatments accurately.
Blood Pressure Category Calculator
Classifies your blood pressure reading into standard AHA categories — from Normal to Hypertensive Crisis — and estimates your overall cardiovascular risk score by factoring in age and additional risk factors. Use it to interpret a home or clinic reading.
Heart Rate Training Zones Calculator
Finds your target heart rate for each training zone using either the simple percentage-of-max method or the more precise Karvonen formula. Use it to structure cardio workouts for fat burning, aerobic base, or peak performance.
Pregnancy Due Date & Week Calculator
Calculates your estimated due date, current pregnancy week, and trimester from your last menstrual period or conception date. Ideal for first-trimester planning and tracking gestational milestones.
Ideal Weight Calculator
Estimates your ideal body weight in kilograms using four established clinical formulas — Hamwi, Devine, Robinson, and Miller — based on height and gender. Useful for setting realistic weight-loss or fitness goals.
Blood Alcohol Content (BAC) Calculator
Estimates your blood alcohol content (BAC) as a percentage and predicts when you will reach zero based on drinks consumed, body weight, gender, and time elapsed. Use it to make informed decisions before driving or operating machinery.