Toolsloft

Health & Fitness Calculators

70 free tools, grouped by topic.

Pregnancy & Fertility

  • Adult Height PredictorPredict how tall a child will be as an adult from the parents' heights, using the Tanner mid-parental method. Works in metric or imperial with a typical range.
  • Baby Height PredictorPredict a child's adult height from the parents' heights with the Tanner mid-parental method, plus the likely range. Free and private.
  • Conception Date CalculatorEstimate the likely conception date and a conception window from either a due date or the first day of your last period.
  • IVF Due Date CalculatorCalculate your IVF due date from your egg retrieval or embryo transfer date. Supports 3-day and 5-day embryo transfers with a precise conception date.
  • Ovulation CalculatorEstimate your ovulation date, fertile window, and next period from your last period, cycle length, and luteal phase. Free and instant.
  • Period CalculatorPredict your upcoming periods, ovulation day, and fertile window from the start of your last period and your cycle length.
  • Pregnancy Trimester CalculatorSee the start and end dates of each pregnancy trimester and which trimester you are in. Works from your last period or your due date.
  • Pregnancy Week CalculatorEstimate your due date, gestational age in weeks and days, trimester, and days remaining from your last menstrual period. Free and instant.
  • Pregnancy Weight Gain CalculatorSee the recommended pregnancy weight-gain range for your pre-pregnancy BMI using IOM 2009 guidelines, for single or twin pregnancies. Free and private.

Calories & Nutrition

  • BMR CalculatorEstimate your basal metabolic rate, the calories your body burns at rest, using the Mifflin-St Jeor, Harris-Benedict, or Katch-McArdle equation.
  • Caffeine Half-Life CalculatorEstimate how much caffeine is left in your body after a set number of hours, using exponential decay and an adjustable half-life.
  • Calorie CalculatorCalculate daily calories to lose, maintain, or gain weight from your BMR and activity level. Free calorie calculator using Mifflin-St Jeor.
  • Calorie Deficit CalculatorTurn a daily calorie deficit into a daily target and projected weekly and monthly weight loss. Free and instant.
  • Calories Burned CalculatorEstimate calories burned from activity MET, body weight, and minutes using the ACSM formula. Free and instant.
  • Calories Burned Running CalculatorEstimate calories burned running from your pace, weight, incline, and time using the ACSM running equation. Free.
  • Calories Burned Walking CalculatorEstimate calories burned walking from your pace, weight, incline, and time using the ACSM walking equation. Free.
  • Carbohydrate CalculatorConvert a daily calorie target and carb percentage into grams of carbohydrate per day and per meal. Free.
  • Daily Calorie Needs CalculatorEstimate your daily calorie needs with the Institute of Medicine EER equations from your age, sex, weight, height, and activity. Free and private.
  • Fat Intake CalculatorConvert a daily calorie target and fat percentage into grams of dietary fat, with a saturated-fat limit. Free.
  • Glycemic Load CalculatorCalculate the glycemic load of a food from its glycemic index and carbohydrate content per serving. Classifies the result as low, medium, or high.
  • Harris-Benedict CalculatorEstimate BMR and daily calorie needs with the revised Harris-Benedict equation and standard activity factors. Free and private.
  • IIFYM CalculatorCalculate your IIFYM macros: daily calories plus protein, carb, and fat grams for cutting, maintaining, or bulking. Free and private.
  • Katch-McArdle CalculatorEstimate BMR and daily calories with the Katch-McArdle formula, which uses lean body mass and your body-fat percentage. Free and private.
  • Keto CalculatorCalculate your daily keto macros, carbs, protein, and fat, from your body stats and goal. Free ketogenic diet calculator using a 5/25/70 split.
  • Macro CalculatorTurn a daily calorie target into grams of protein, carbs, and fat for any macro split. Free macronutrient calculator with no signup.
  • Macros for Bulking CalculatorGet your bulking macros: calories, protein, carbs, and fat for muscle gain. Based on your TDEE, a calorie surplus, and a training-friendly split.
  • Macros for Cutting CalculatorGet your cutting macros: calories, protein, carbs, and fat for fat loss. Based on your TDEE, a calorie deficit, and a high-protein split.
  • Maintenance Calorie CalculatorFind the daily calories that keep your weight steady. Uses the Mifflin-St Jeor equation and your activity level to estimate maintenance calories (TDEE).
  • METs CalculatorConvert METs, body weight, and time into calories burned using the ACSM metabolic equation. Enter the MET value of an activity to estimate its energy cost.
  • Net Carbs CalculatorCalculate net carbs from total carbohydrates, fiber, and sugar alcohols. Free and accurate.
  • Protein Intake CalculatorFind your daily protein target in grams from your body weight and goal. Ranges based on sports-nutrition guidelines for maintenance, muscle, and fat loss.
  • RMR CalculatorEstimate your resting metabolic rate (RMR): the calories your body burns at rest. Uses the Mifflin-St Jeor equation from your sex, weight, height, and age.
  • TDEE CalculatorEstimate your total daily energy expenditure, the calories you burn per day, from your BMR and activity level. Free maintenance-calorie calculator.
  • Water Intake CalculatorEstimate your daily water intake from body weight and exercise. See your target in litres, millilitres, and ounces. Free and instant.
  • Zigzag Calorie CalculatorPlan a zig-zag calorie cycling week: high and low days that average to your target. Free calorie cycling calculator, private and in-browser.

Fitness & Performance

  • Cooper Test VO2 Max CalculatorEstimate your VO2 max from a 12-minute Cooper run. Enter the distance you covered in meters to get your aerobic fitness score.
  • DOTS CalculatorCalculate your DOTS score from body weight, sex, and powerlifting total. The modern strength formula that compares lifters across weight classes.
  • Heart Rate Zone CalculatorCalculate your five cardio training zones from your age. Shows the beats-per-minute range for each zone as a percentage of maximum heart rate.
  • Karvonen Heart Rate CalculatorFind your target heart rate zone with the Karvonen formula, using your age and resting heart rate. Returns the 50 to 85 percent training range in beats per minute.
  • Max Heart Rate CalculatorEstimate your maximum heart rate from your age with the Fox (220 minus age) and Tanaka formulas. Free and instant.
  • One Rep Max CalculatorEstimate your one-rep max from a weight and rep count using the Epley, Brzycki, and Lombardi formulas. Free 1RM calculator with the average.
  • Running Pace CalculatorCalculate your running pace per km and per mile plus average speed from a distance and finish time. Free and instant.
  • Steps to Miles CalculatorConvert steps into miles and kilometers based on your height. Estimates your walking stride length and turns a step count into distance walked.
  • Target Heart Rate CalculatorCalculate your target heart rate zones with the Karvonen method from your age and resting heart rate. See moderate and vigorous ranges in bpm.
  • Wilks CalculatorCalculate your Wilks score from your body weight, sex, and powerlifting total. Compares strength fairly across weight classes.

Body & Weight

  • Adjusted Body Weight CalculatorCalculate ideal and adjusted body weight from height, weight, and sex using the Devine formula. Used in clinical dosing for people above their ideal weight.
  • Army Body Fat CalculatorEstimate body-fat percentage with the US Army AR 600-9 tape method from a few measurements in inches. Free and private.
  • BMI CalculatorFind your body mass index from height and weight, in metric or imperial units, with the standard weight category. Free and instant.
  • BMI Calculator for MenCalculate BMI for men from height and weight, in metric or imperial units, with the standard weight category.
  • BMI Calculator for WomenCalculate BMI for women from height and weight, in metric or imperial units, with the standard weight category.
  • Body Fat CalculatorEstimate body-fat percentage with the US Navy tape method from a few measurements, plus the fitness category it falls in. Free and private.
  • Body Surface Area (BSA) CalculatorCalculate body surface area from height and weight using the Mosteller and Du Bois formulas. Reports BSA in square meters, the value used for dosing and clinical indexing.
  • FFMI CalculatorCalculate your Fat-Free Mass Index (FFMI) and normalized FFMI from your weight, height, and body fat percentage. A muscularity score that BMI cannot give.
  • Goal Weight Date CalculatorProject the date you reach your goal weight from a steady weekly loss rate, plus the daily calorie deficit it takes. Free and private.
  • Healthy Weight Range CalculatorFind your healthy weight range by height using the WHO normal BMI band of 18.5 to 25. Metric or imperial. Free.
  • Ideal Weight CalculatorEstimate a healthy target weight for your height using the Devine, Robinson, Miller, and Hamwi formulas. Results in kilograms, free and instant.
  • Lean Body Mass CalculatorEstimate lean body mass in kilograms using the Boer, James, and Hume formulas. Free and accurate.
  • Navy Body Fat CalculatorEstimate body fat with the US Navy tape method. Enter height, neck, and waist in cm (plus hip for women) for a body-fat percentage.
  • Relative Fat Mass CalculatorEstimate body fat percentage from height and waist using the Relative Fat Mass (RFM) formula. No calipers needed.
  • Skinfold Body Fat CalculatorEstimate body fat from three caliper skinfold measurements using the Jackson-Pollock formula. Men use chest, abdomen, and thigh; women use triceps, suprailiac, and thigh.
  • Waist to Height Ratio CalculatorCalculate your waist-to-height ratio and see the health band it falls into. Keep your waist under half your height. Free and private.
  • Waist to Hip Ratio CalculatorCalculate your waist-to-hip ratio and see the WHO risk category. Enter your waist and hip measurements for an instant result. Free and private.
  • Weight Loss Percentage CalculatorSee how much weight you have lost and what percent of your starting weight that is, in pounds or kilograms. Track progress toward the 5% and 10% milestones that matter for health.

Health Metrics

  • A1c to Average Glucose CalculatorConvert HbA1c to estimated average glucose (eAG) in mg/dL and mmol/L. Free and private.
  • Blood Alcohol (BAC) CalculatorEstimate blood alcohol concentration with the Widmark formula from your weight, sex, drinks, and time. For education only, not a measure of fitness to drive.
  • Blood Pressure Category CalculatorEnter a systolic and diastolic reading to see its American Heart Association category, from normal to hypertensive crisis.
  • Cholesterol Ratio CalculatorCalculate your total-to-HDL, LDL-to-HDL, and triglyceride-to-HDL cholesterol ratios from a lipid panel. Shows how your HDL compares with your other numbers.
  • Pack Year CalculatorCalculate smoking pack-years from cigarettes per day and years smoked. Free and private.
  • Sleep CalculatorFind the best bedtime or wake-up time based on 90-minute sleep cycles so you wake up feeling rested. Free.
  • Sleep Cycle CalculatorFind the best times to go to sleep or wake up based on 90-minute sleep cycles. Enter a wake time for bedtimes, or a bedtime for wake times.