Health

Track your fitness and health indicators.

• 1RM Calculator: One Rep Max with the Epley Formula – Enter the weight lifted and the number of reps to estimate your one rep max and your loads from 50 to 95%.
• Water Intake Calculator: How Much Water to Drink a Day – Enter weight, sex, exercise and climate to estimate how much water to drink daily, excluding water from food.
• Cardiac Coherence Breathing Exercise: Guided 5-5 Timer – Follow the visual guide: breathe in for 5 seconds, out for 5 seconds, 6 breaths per minute, with a session timer.
• IIFYM Macro Calculator: Protein, Carbs and Fat – Start from your calorie needs and your goal to get your daily grams of protein, carbohydrates and fat.
• Intermittent Fasting Timer for 16/8, 18/6 and OMAD – Start a fasting session and track elapsed time, time left and the metabolic stage for your chosen protocol.
• Heart Rate Zone Calculator: Target Heart Rate (Karvonen) – Enter your age and resting heart rate to get your target heart rate and 5 training zones in bpm, with Karvonen or % of max HR (220 − age or Tanaka).
• BMI Calculator: Body Mass Index and WHO Categories – Enter your weight and height to get your BMI and its WHO category, from underweight to overweight and obesity.
• Calorie Calculator: BMR (Schofield), TDEE, Deficit, Macros – Calculate your BMR, daily energy expenditure (TDEE), target calories for a deficit or surplus and your macro split in grams, meal by meal.
• Pregnancy Due Date Calculator: Weeks and Key Dates – Enter the first day of your last period and cycle length to get your due date and current week of pregnancy.
• US HSA vs FSA Calculator: Tax Savings on Health Costs – Enter your contributions and federal and state tax rates to compare the tax savings of an HSA and an FSA.
• Caffeine Half-Life Calculator: Bedtime Cutoff for Sleep – Track daily coffee and caffeine intake half-life breakdown, calculate residual bloodstream mg at bedtime, and determine your optimal cutoff time.
• Ovulation Calculator: Fertile Window, Next Periods, Due Date – Estimate ovulation, fertile days and peak fertility over 3 cycles, plus the date for a pregnancy test and the estimated due date.
• Dog Age Calculator: Dog and Cat Years to Human Years – Convert your pet's age into human years using indicative weight-adjusted physiological curves and life stage wellness guidelines.
• US Navy Body Fat Percentage Calculator (Tape Measure Method) – Estimate your body fat percentage, fat mass, lean body mass, and ACE fitness category with simple circumference measurements.
• Blood Pressure Calculator: AHA Category and Pulse Pressure – Classify systolic and diastolic blood pressure readings against American Heart Association standards, pulse pressure, and MAP.
• 90 Minute Sleep Cycle Calculator: Best Bedtime and Wake-Up – Find bedtimes or wake-up times in 90-minute cycles, your sleep debt over 7 nights and the right nap length.
• Weight Loss Date Calculator: Calorie Deficit to Goal Weight – Calculate your exact target date for weight loss based on daily caloric deficit, Mifflin-St Jeor BMR, TDEE, and customized macronutrients.
• HSA Calculator: Triple Tax Advantage and Investment Growth – Project long-term compound growth of an invested Health Savings Account, compare vs taxable accounts, and leverage the Stealth IRA strategy.
• Blood Alcohol Calculator (Widmark): BAC and Time to Sober Up – Estimate your blood alcohol (g/L), its peak and the time to get below 0.5 g/L, below 0.2 g/L and back to zero, from weight, drinks and timing.
• Sunscreen Calculator: SPF, UV Index and Safe Exposure Time – Calculate safe sun exposure time before burning based on Fitzpatrick skin phototype, local UV index, and sunscreen SPF rating.
• Mattress Firmness & Ergonomic Pillow Thickness Selector – Determine optimal mattress firmness level and ergonomic pillow height tailored to body weight, height, and preferred sleeping posture.
• Steps to km Calculator: Distance in Miles and Calories – Convert pedometer steps into real distance and calories burned factoring in biological stride length and walking pace.
• Bike Gear Ratio Calculator: Development and Speed – Calculate gear ratio (chainring ÷ sprocket), development in metres per pedal turn and speed at your cadence, for every chainring and sprocket.
• Race Time Predictor: Riegel Formula for Half and Marathon – Predict your half marathon, marathon or 10K time from a recent race with the Riegel formula (T2 = T1 × (D2/D1)^1.06), plus the matching pace.
• Running Pace Calculator: min/km, km/h and Split Times – Work out your marathon, half or 10K pace, convert km/h to min/km or mph and get a full split table, with an optional negative split.
• Cosmetic Ingredients by Barcode: INCI List Lookup – Enter or scan the barcode of a cosmetic to read its INCI ingredients list, labels and period after opening as published by Open Beauty Facts.
• Nutri-Score Barcode Lookup: Grade, NOVA, Additives – Type or scan a food barcode to see its Nutri-Score, NOVA group, Eco-Score, additives and allergens as published by Open Food Facts.
• Drug side effects lookup: FDA adverse event reports (FAERS) – Most reported side effects for a drug in the FDA's FAERS database, with report counts and shares. openFDA data; reports do not prove causation.
• Blood Glucose Converter: mg/dL, mmol/L, HbA1c, Vitamin D – Convert blood glucose between mg/dL, mmol/L and g/L, HbA1c to mmol/mol and average glucose, plus vitamin D and cholesterol units, with sourced thresholds.
• Corrected Age Calculator for Premature Babies – Work out a premature baby’s corrected age from the birth date and gestational age, in weeks and months, plus postmenstrual age and WHO category.
• Hearing test: pure tones by ear and an indicative audiogram – Check your hearing with headphones, one ear at a time, from 250 to 8,000 Hz: ascending method in 5 dB steps, indicative audiogram and the gap between your ears.
• Binaural beats generator: carrier, beat and EEG bands – Two pure tones, one per ear, with adjustable carrier and beat (0.5 to 30 Hz), delta to beta presets and an honest summary of the published research.
• Creatine dosage calculator: loading, maintenance, daily plan – Work out how much creatine to take for your weight: optional 0.3 g/kg loading phase, 3 to 5 g daily maintenance and a day-by-day plan in grams and scoops.
• Eye test: indicative visual acuity check and Amsler grid – On-screen eye test calibrated with a bank card: tumbling E or Landolt C drawn to scale, one eye at a time, with decimal, Snellen and logMAR results.
• FTP calculator: 20-minute test, ramp test and Coggan zones – Work out your FTP from a 20-minute test (× 0.95) or a ramp test (75% of best minute), your watts per kilo and the 7 Coggan power zones in watts.
• VO2 max calculator: Cooper, Rockport, 1.5 mile, heart rate – Estimate your VO2 max from four published field tests (Cooper 12-minute run, Rockport walk, 1.5-mile test, heart rate ratio) and compare it by age and sex.
• White noise, pink and brown noise with a sleep timer – Play looping white, pink or brown noise with a capped volume, a sleep timer and a gentle fade-out, plus distance and volume advice for babies.
• Baby sleep schedule: hours by age, naps and daily plan – How much should your child sleep from birth to 5 years? Recommended 24-hour totals (AASM, AAP), naps, a day plan from wake-up time and safe sleep reminders.