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Health & Fitness Calculators

BMI, calorie, body fat, macros and training calculators built on established health formulas.

100 calculatorsBody metrics, nutrition & training

Most popular

BMI CalculatorCalculate your Body Mass Index (BMI) and see which weight category you fall into.Calorie CalculatorEstimate your daily calorie needs to maintain, lose or gain weight.Body Fat CalculatorEstimate body fat percentage using the U.S. Navy circumference method.Keto Macro CalculatorCalculate your daily fat, protein, and carb targets for a ketogenic diet based on your calorie needs.

All calculators

BMI Prime CalculatorCalculate BMI Prime - the ratio of your BMI to the upper limit of normal BMI (25).
BMR CalculatorCalculate your Basal Metabolic Rate - calories burned at complete rest.
TDEE CalculatorCalculate your Total Daily Energy Expenditure based on activity level.
Army Body Fat CalculatorEstimate body fat percentage using the U.S. Army circumference-based method.
Ideal Weight CalculatorEstimate your ideal body weight using the Devine formula.
Healthy Weight Range CalculatorFind the healthy weight range for your height based on normal BMI (18.5–24.9).
Lean Body Mass CalculatorEstimate your lean body mass using the Boer formula.
Macro CalculatorCalculate your daily protein, carb and fat targets based on calorie goal.
Daily Fat Intake CalculatorCalculate a healthy daily fat intake range based on total calories.
Protein Intake CalculatorCalculate your recommended daily protein intake based on body weight and activity.
Water Intake CalculatorEstimate your recommended daily water intake based on body weight.
Running Pace CalculatorCalculate your running pace per mile or kilometer from distance and time.
VO2 Max CalculatorEstimate VO2 max from resting and maximum heart rate (non-exercise method).
One Rep Max CalculatorEstimate your one-rep max using the Epley formula.
Target Heart Rate CalculatorCalculate your target heart rate training zones using the Karvonen formula.
Heart Rate Training Zones CalculatorCalculate your 5 heart-rate training zones based on maximum heart rate.
Calories Burned CalculatorEstimate calories burned during exercise based on activity, weight and duration.
Steps to Calories CalculatorConvert your daily step count into an estimated calories burned.
Waist-to-Hip Ratio CalculatorCalculate your waist-to-hip ratio, a marker of health risk related to body fat distribution.
Body Adiposity Index CalculatorEstimate body fat percentage using hip circumference and height (BAI method).
Blood Alcohol Calculator (BAC)Estimate blood alcohol content using the Widmark formula. For education only - never drive after drinking.
Pregnancy Due Date CalculatorEstimate your baby's due date from your last menstrual period.
Ovulation CalculatorEstimate your fertile window and next ovulation date.
Conception Date CalculatorEstimate the likely conception date from your due date.
Pregnancy Weight Gain CalculatorSee the recommended pregnancy weight gain range based on your pre-pregnancy BMI (IOM guidelines).
Sleep CalculatorFind the ideal bedtime or wake-up time based on 90-minute sleep cycles.
Caloric Deficit CalculatorCalculate the daily calorie deficit needed to lose weight at your target rate.
Weight Loss Timeline CalculatorEstimate how many weeks it will take to reach your goal weight at a given calorie deficit.
Smoking Cost CalculatorCalculate how much money smoking costs you over time.
Alcohol Calories CalculatorEstimate the calories in your alcoholic drinks.
Child Height PredictorEstimate a child's adult height using the mid-parental height method.
Body Surface Area CalculatorCalculate your body surface area using the DuBois formula.
Blood Pressure Category CalculatorClassify a blood pressure reading using American Heart Association categories.
Waist-to-Height Ratio CalculatorCalculate your waist-to-height ratio, a simple screening measure for health risk.
Pulse Pressure CalculatorCalculate pulse pressure - the difference between systolic and diastolic blood pressure.
Mean Arterial Pressure (MAP) CalculatorCalculate mean arterial pressure from systolic and diastolic blood pressure readings.
Macro to Calories CalculatorCalculate total calories and the percentage breakdown from your protein, carb and fat grams.
Katch-McArdle BMR CalculatorCalculate BMR using the Katch-McArdle formula, which factors in body fat percentage for a more personalized estimate.
Steps to Miles CalculatorConvert your daily step count into an estimated distance walked.
Sweat Rate CalculatorEstimate your sweat rate during exercise to plan fluid replacement.
Heart Rate Recovery CalculatorCalculate your heart rate recovery - a fitness indicator based on how fast your heart rate drops after exercise.
Swim Pace CalculatorCalculate your swimming pace per 100 meters from distance and time.
Protein Per Meal CalculatorSplit your daily protein target evenly across meals.
Cycling FTP Training Zones CalculatorCalculate your cycling power training zones from your Functional Threshold Power (FTP).
Daily Fiber Intake CalculatorCalculate a recommended daily fiber intake based on your calorie needs.
Intermittent Fasting Window CalculatorCalculate your eating and fasting window times for common intermittent fasting schedules.
Daily Sodium Intake CalculatorTrack your daily sodium intake against recommended limits.
Added Sugar Intake CalculatorTrack your daily added sugar intake against recommended limits.
Daily Calcium Intake CalculatorCheck your daily calcium intake against the recommended amount for your age and sex.
Daily Iron Intake CalculatorCheck your daily iron intake against the recommended amount for your age and sex.
Daily Vitamin D Intake CalculatorCheck your daily vitamin D intake against the recommended amount for your age.
Daily Potassium Intake CalculatorCheck your daily potassium intake against the recommended amount for your sex.
Daily Magnesium Intake CalculatorCheck your daily magnesium intake against the recommended amount for your age and sex.
Caffeine Half-Life CalculatorEstimate how much caffeine remains in your system over time based on its average half-life.
Alcohol Elimination Time CalculatorEstimate how long it will take for your body to fully eliminate alcohol based on your current BAC.
Resting Heart Rate Fitness Level CalculatorSee how your resting heart rate compares to typical fitness level categories for your age.
Grip Strength Percentile CalculatorSee how your hand grip strength compares to population norms for your age and sex.
Sit and Reach Flexibility Test CalculatorRate your lower back and hamstring flexibility using the standard sit-and-reach test scale.
Push-Up Test Fitness Level CalculatorRate your upper body strength endurance based on the standard push-up fitness test.
Plank Time Fitness Level CalculatorRate your core strength endurance based on how long you can hold a standard plank.
Body Recomposition Timeline CalculatorEstimate a realistic timeline for simultaneous fat loss and muscle gain (body recomposition).
Daily Step Goal CalculatorCalculate a recommended daily step goal based on your current activity level and fitness objective.
A1C to Average Blood Glucose CalculatorConvert an A1C percentage to its estimated average blood glucose (eAG) level.
Cholesterol Ratio CalculatorCalculate your total cholesterol to HDL ratio, a commonly used cardiovascular risk indicator.
Metabolic Age CalculatorEstimate your metabolic age by comparing your BMR to population averages for different ages.
Estimated Lung Capacity CalculatorEstimate your predicted vital lung capacity based on age, height, and sex.
Skinfold Body Fat CalculatorEstimate body fat percentage from skinfold caliper measurements using the Jackson-Pollock 3-site method.
Waist Circumference Health Risk CalculatorCheck your waist circumference against health risk thresholds for your sex.
Harris-Benedict BMR CalculatorCalculate your Basal Metabolic Rate using the revised Harris-Benedict equation.
Muscle Mass Percentage CalculatorEstimate your skeletal muscle mass percentage from body weight, height, age, and sex.
EPOC Afterburn Calories CalculatorEstimate additional calories burned after a workout from excess post-exercise oxygen consumption (EPOC), the "afterburn effect."
Race Time PredictorPredict your finish time for a longer race distance based on a recent shorter race result.
Swim SWOLF CalculatorCalculate your SWOLF score, a combined measure of swimming stroke efficiency (time plus stroke count).
Rowing Pace CalculatorCalculate rowing split time (per 500m) and total time for a given distance and pace.
Exercise Dehydration Percentage CalculatorCalculate the percentage of body weight lost as fluid during exercise, an indicator of dehydration severity.
RPE-Based One Rep Max CalculatorEstimate your one-rep max using an RPE (Rate of Perceived Exertion) chart instead of the standard reps-based formula.
Acute:Chronic Training Load Ratio CalculatorCalculate your acute:chronic workload ratio (ACWR), a sports science metric used to monitor injury risk from training load spikes.
Cunningham BMR CalculatorCalculate your Basal Metabolic Rate using the Cunningham equation, which is based on lean body mass rather than total weight.
Fatmax Heart Rate Zone CalculatorEstimate the heart rate zone where your body burns the highest proportion of fat as fuel during exercise.
Exercise MET Value CalculatorCalculate calories burned from an activity's MET (Metabolic Equivalent of Task) value, body weight, and duration.
Daily Vitamin C Intake CalculatorCheck your daily vitamin C intake against the recommended amount for your sex and smoking status.
Daily Zinc Intake CalculatorCheck your daily zinc intake against the recommended amount for your sex.
Daily Omega-3 Intake CalculatorCheck your daily omega-3 fatty acid intake against commonly recommended amounts.
Fasting Blood Glucose Classification CalculatorCheck where a fasting blood glucose reading falls relative to normal, prediabetes, and diabetes ranges.
Pregnancy Trimester CalculatorFind out which trimester of pregnancy you're in and how many weeks remain, based on your due date.
Breastfeeding Calorie Needs CalculatorEstimate additional daily calorie needs while breastfeeding, based on your pre-pregnancy TDEE.
Bone Mass Percentage CalculatorEstimate your bone mass and its percentage of total body weight using a standard anthropometric formula.
Altitude Acclimatization Days CalculatorEstimate how many days of acclimatization are recommended before ascending further at high altitude.
Lactate Threshold Heart Rate EstimatorEstimate your lactate threshold heart rate, a key training zone marker for endurance athletes.
Step Length by Height CalculatorEstimate your average walking and running step length based on your height, for more accurate step counter calibration.
Post-Workout Protein Timing CalculatorCalculate the recommended protein amount for your post-workout meal based on body weight.
Resting Respiratory Rate CheckerCheck whether your resting breathing rate falls within the typical normal range for adults.
Weekly Workout Frequency Recommendation CalculatorGet a recommended weekly workout frequency based on your fitness goal and experience level.
Resting Heart Rate Trend TrackerCompare your current resting heart rate to a recent baseline average to flag possible overtraining or illness.
Creatine Loading Dose CalculatorCalculate creatine loading and maintenance phase doses based on body weight.
Caloric Surplus for Muscle Gain CalculatorCalculate a recommended daily calorie surplus for lean muscle gain based on your experience level.

About Health & Fitness Calculators

These use the same published formulas clinicians and trainers reference - Mifflin-St Jeor for calorie needs, the U.S. Navy method for body fat, standard BMI ranges - rather than invented approximations. They're built to give you an honest, well-sourced estimate to work from, not a diagnosis; anything about a real medical concern belongs with a doctor, not a calculator.

Related reading

What a Realistic Weight Loss Timeline Actually Looks LikeWeight loss apps often show a straight-line prediction, but real progress isn't linear. Here's how to calculate a realistic timeline and why it bends.How Big Should Your Calorie Deficit Actually Be?Too aggressive a deficit backfires. Here's how to calculate a calorie deficit that matches a realistic, sustainable weight loss rate.Why Waking Up Mid-Sleep-Cycle Makes You Feel WorseSleep happens in roughly 90-minute cycles, and waking up in the middle of one feels far worse than waking at the end. Here's the math behind bedtime planning.