Browse 37 free calculators in the Health & Fitness category.
BMI Calculator - Check your Body Mass Index using height and weight. The calculator classifies your result into WHO categories from underweight to class III obesity and shows the healthy weight range for your height.
BMR & TDEE Calculator - Calculate your Basal Metabolic Rate and Total Daily Energy Expenditure using the Mifflin-St Jeor equation. Get target calories for cutting, maintenance or bulking with a protein, fat and carb split.
Ideal Weight Calculator - Find your ideal weight range using three clinical formulas: Broca, Devine and Robinson. Results adjust for sex, body frame and age to give a realistic target rather than a single number.
WHR Calculator (Waist-to-Hip Ratio) - Measure where your body stores fat - not just how much. The waist-to-hip ratio separates apple from pear body shapes and flags cardiovascular risk faster than BMI alone.
Body Fat Percentage Calculator - A tape measure, a scale and the U.S. Navy formula - that is all it takes. Enter neck, waist and hip circumference to get your body fat percentage, lean body mass and a fitness category based on ACSM guidelines.
One Rep Max (1RM) Calculator - Bench 80 kg for 5 reps - what is your true max? Three proven formulas (Epley, Brzycki, Lombardi) estimate your 1RM and generate a full training plan from 50% to 95% intensity.
Calories Burned Calculator - Pick an activity, enter your weight and duration - get the calorie burn. MET-based formula covers 23 activities from walking to HIIT. Shows hourly burn rate, time to burn 500 kcal and food equivalents.
Water Intake Calculator - One number, four adjustments. Enter your weight, sex, activity level and temperature - get your daily water target in liters and glasses. Includes a drinking schedule and dehydration warning signs.
Protein Intake Calculator - Same weight, three different protein targets. Your goal (fat loss, maintenance, muscle gain), training intensity and age determine how many grams per kilogram you actually need. ISSN-based formula with meal distribution and food sources.
Training Heart Rate Calculator - Five zones, one number - your age. Enter your age and optional resting heart rate to get personalized training zones from warm-up to HIIT. Two methods: simple (220 - age) and Karvonen (uses heart rate reserve for better accuracy).
Running Pace Calculator - Distance and time in, pace and race predictions out. Enter any completed run and get your pace in min/km, speed in km/h, plus predicted finish times for 5K, 10K, half marathon and marathon using the Riegel formula.
Pregnancy Calculator - The invisible countdown from your last period to delivery day. Enter your LMP date and optional cycle length to get your estimated due date, current week, trimester, conception date and days remaining - all based on the Naegele rule.
Menstrual Cycle Calculator - Enter your last period date and cycle length to predict your next period, ovulation day and fertile window. Covers all four cycle phases with symptom guidance for each stage.
Macronutrient Calculator - Same calories, three different macro splits. Enter your weight, height, age and goal - cutting, maintenance or bulking - and get exact grams of protein, fat and carbs per day, plus per-meal breakdown for 3 or 5 meals.
Calorie Deficit Calculator - You want to lose 10 kg but have no idea how long it takes or how little to eat. Enter your current weight, target weight and preferred pace - the calculator shows daily calories, a week-by-week weight projection and warns you if the deficit drops below safe minimums.
Calorie Surplus Calculator - Same TDEE, three different surpluses - and only one builds mostly muscle. Enter your weight, height, age and bulking style to get a daily calorie target, macro split and a week-by-week weight projection.
Child BMI Calculator - Is your child's weight normal for their age? Enter sex, age, weight and height - the calculator shows BMI, WHO/CDC percentile ranking and whether the result falls in the underweight, normal, overweight or obese range.
Child Growth Predictor - Your 8-year-old is 128 cm - will they end up at 170 or 185? Enter the child's sex, age and height plus both parents' heights. Two methods (Tanner and proportional) produce a combined adult height forecast accurate to about 5 cm.
Child Weight Percentile Calculator - Where does your child's weight rank among peers? Enter sex, age and weight - the calculator compares against WHO reference data and shows the percentile position on the weight-for-age growth chart.
Pregnancy Heart Rate Calculator - Your resting heart rate climbs by 10-25 bpm during pregnancy and the safe exercise ceiling drops with each trimester. Enter your age, trimester, resting pulse and pre-pregnancy fitness level to get a personalized safe training heart rate range based on ACOG guidelines.
Breathing Rate Calculator - Count your breaths per minute during exercise and find out whether you are in the normal zone, approaching the ventilatory threshold or hyperventilating. Get activity-specific breathing technique tips and estimated minute ventilation.
VO2max Calculator - Estimate your VO2max without a lab. Cooper test, Rockport walk test or age-based formula. Get your aerobic fitness classification, percentile rank and improvement potential based on sex and age norms.
BAC Calculator (Blood Alcohol Content) - Same weight, same drinks, different BAC - sex and body composition change everything. Enter what you drank and when, get your estimated blood alcohol level, peak BAC, elimination timeline and hours until sober.
Sobering Time Calculator - Enter what you drank or your current breathalyzer reading, and get an hour-by-hour elimination timeline. The calculator shows when your BAC drops to zero and when you cross each legal driving limit.
Child Fever Calculator - A child's forehead feels warm but the thermometer reads 37.4. Is that a fever? Enter the reading, measurement site and age - the calculator corrects to rectal equivalent, classifies the fever grade and suggests approximate paracetamol and ibuprofen doses by weight.
Walk-Run Calories Calculator - Exact calorie burn for any walk-run interval mix, adjusted for your weight and pace. Enter running and walking phases separately - the calculator applies correct MET values to each and gives you a combined total with distance, average pace and per-kilometer burn.
Weather Pace Adjustment Calculator - Running in July heat? Your comfortable 5:00 pace is really 5:15 effort. Enter your baseline pace, temperature, humidity, wind and surface - the calculator shows the adjusted pace and breaks down each factor's impact in seconds.
Interval Training Calculator - Planning a track session? Pick your rep distance, enter the target pace, set the number of reps and recovery type - the calculator builds a series-by-series plan with timed rest intervals based on the work-to-rest ratio for your chosen distance.
Alcohol Calories Calculator - A pint of lager has more calories than a glazed doughnut, but no label tells you that. Select your drink, enter the volume - the calculator shows total kcal, grams of pure ethanol and everyday food equivalents you can picture.
Sugar Content Calculator - One can of cola covers 140% of the WHO daily sugar limit - before lunch. Pick a product from 50+ items across six categories, set the serving count and see grams, teaspoons, sugar cubes and a WHO limit progress bar that turns red faster than you expect.
Fiber Intake Calculator - Five food groups, one number. Pick up to five products from 36 items, see total grams, percentage of the 25-38 g daily target and a progress bar with swap suggestions when you fall short.
Blood Pressure Calculator - What do the two numbers on your monitor actually mean? Enter systolic and diastolic readings, choose office or home measurement, and get an ESC/ESH classification, pulse pressure, MAP and isolated systolic hypertension detection.
Resting Heart Rate Calculator - Every beat above 75 at rest costs your heart 14,000 extra contractions per day. Enter your pulse, age, sex and activity level to get an AHA classification, estimated VO2max and a daily heartbeat count that puts your fitness into perspective.
Visceral Fat Calculator - Same BMI, different risk - two people at 78 kg can carry vastly different amounts of visceral fat. Enter your waist circumference, hip circumference, height, age and sex to get a Visceral Fat Rating, WHR (waist-to-hip ratio), WHtR (waist-to-height ratio) and WHO waist classification with a personalised reduction target.
Rest Between Sets Calculator - How long should you rest between sets? Pick your goal, the lift and your experience, add reps and RIR, and get one rest time from the ACSM ranges plus the length of the whole workout.
FMS Score Calculator - Functional Movement Screen scoring in one place: 7 tests with left and right sides, 3 pain clearing tests, the total out of 21, the asymmetries and where to start correcting.
Kids Physical Activity Calculator - Check how much physical activity your child gets against the WHO guidelines for ages 0 to 17: minutes of movement, active days, tummy time, stroller time, screens and sleep.