Health & Fitness
21 free tools — all run in your browser, no account needed.
BMI CalculatorCalculate your Body Mass Index using metric or imperial units with category breakdown.Use tool →Sleep CalculatorFind the best bedtime or wake-up time based on 90-minute sleep cycles. Wake up refreshed with this free sleep cycle calculator.Use tool →TDEE CalculatorCalculate your Total Daily Energy Expenditure using the Mifflin-St Jeor formula. Find calorie targets for weight loss, maintenance, or muscle gain.Use tool →Ideal Weight CalculatorCalculate your ideal body weight using four clinical formulas: Devine, Robinson, Miller, and Hamwi. Supports metric and imperial units.Use tool →Heart Rate Zone CalculatorFind your 5 heart rate training zones based on age or max heart rate. Includes the Karvonen formula with fat burn, aerobic, and VO₂ max zones.Use tool →Body Fat CalculatorEstimate body fat percentage using the US Navy circumference method. Enter height, neck, waist, and hip measurements to see your body fat category. Metric and imperial supported.Use tool →Weight Loss CalculatorCalculate how long it will take to reach your weight loss goal. Choose your pace, see the required daily calorie deficit, and get a month-by-month weight milestone breakdown.Use tool →Running Pace CalculatorConvert running pace and speed with race finish time estimates.Use tool →Calorie Burn CalculatorEstimate calories burned using activity MET, body weight, and workout duration.Use tool →Daily Water Intake CalculatorEstimate daily hydration target in ml and liters using weight, activity, and climate.Use tool →Breathing Exercise TimerFollow guided breathing exercises to reduce stress, improve focus, or fall asleep. Choose Box Breathing, 4-7-8, Calm Breathing, or Energizing Breath with an animated visual guide.Use tool →Macro CalculatorCalculate daily protein, carbohydrate, and fat targets based on your TDEE and goal. Enter your stats and choose to lose weight, maintain, or build muscle — get gram and calorie breakdowns.Use tool →Weight TrackerLog your weight over time, visualize progress with a line chart, track BMI, and set a goal weight — all stored privately in your browser using localStorage.Use tool →One Rep Max CalculatorEstimate your one rep max from any weight and rep count using six recognised formulas, with a full percentage table and a warm-up set generator.Use tool →VO2 Max CalculatorEstimate VO2 max from the Cooper test, the 1.5-mile run, resting heart rate or the Rockport walk, and compare it against age and sex norms.Use tool →Lean Body Mass CalculatorCalculate lean body mass and fat mass with four clinical formulas, shown as a body-composition breakdown against the ideal range.Use tool →Swim Pace CalculatorConvert between swim time, distance and pace per 100m or 100yd, with per-50 split tables and predicted finish times for common race distances.Use tool →Cycle & Fertility CalendarPredict your next periods, fertile window and ovulation day, shown on a colour-coded calendar. Log real period dates to refine the predictions. Stored only in your browser.Use tool →Eye Test ChartDisplay a correctly scaled Snellen or Tumbling E eye chart. Calibrate your screen, work through the lines, and get an approximate visual acuity reading.Use tool →Child Growth Percentile ChartPlot a child's height and weight against reference percentile curves, track measurements over time, and see which percentile they fall on.Use tool →Blood Alcohol EstimatorEstimate blood alcohol content with the Widmark formula and its refinements, with a drink database, a decay curve and the time to sober. An estimate only — never use it to decide whether to drive.Use tool →