Health Calculators
Understand your body with free health calculators — BMI, body fat, BMR and calorie needs, ideal weight, macros, and pregnancy dates. Results come with healthy ranges and plain-language guidance, not just numbers.
Fitness
BMI Calculator
Check your Body Mass Index from your height and weight, see which category you fall in, and find the healthy weight range for your height.
Calorie Calculator
Estimate your daily calorie needs for maintenance or weight change based on your age, sex, height, weight, and activity level using the Mifflin-St Jeor equation.
Body Fat Calculator
Estimate your body fat percentage using the U.S. Navy method from simple tape measurements of your neck, waist, and hips.
BMR Calculator
Calculate your Basal Metabolic Rate — the calories your body burns at complete rest — using the Mifflin-St Jeor, Harris-Benedict, or Katch-McArdle formula.
Ideal Weight Calculator
Find your ideal body weight based on your height, sex, and frame size using the Robinson, Miller, Devine, and Hamwi formulas.
Pace Calculator
Calculate your running or walking pace from distance and time, predict finish times from a target pace, or find how far you can go at a given pace and duration.
Army Body Fat Calculator
Estimate your body fat percentage using the U.S. Army tape-test method and see whether you meet the maximum allowable body fat standard for your age and sex per AR 600-9.
Lean Body Mass Calculator
Estimate your lean body mass (fat-free weight) using the Boer, James, and Hume formulas from your height, weight, and sex.
Healthy Weight Calculator
Find the healthy weight range for your height based on a BMI of 18.5 to 24.9, with the midpoint as a general target.
Calories Burned Calculator
Estimate how many calories you burn during exercise based on the activity, duration, and your body weight using standard MET values from the Compendium of Physical Activities.
One Rep Max Calculator
Estimate your one-rep max (1RM) from a sub-maximal lift using Epley, Brzycki, and Lombardi formulas, with a percentage-based training load table.
Target Heart Rate Calculator
Calculate your five heart rate training zones from your age and resting heart rate. Uses the Karvonen method for personalized zones or simple percentage of max HR.
Pregnancy
Pregnancy Calculator
Estimate your due date, track your current pregnancy week and trimester, see baby size milestones, and view a full 42-week pregnancy timeline.
Pregnancy Weight Gain Calculator
Find out how much weight gain is recommended during your pregnancy based on your pre-pregnancy BMI, and see what you should expect at your current week.
Pregnancy Conception Calculator
Estimate when conception likely occurred based on your current pregnancy week or due date, with a probable date range and fertile window.
Due Date Calculator
Calculate your estimated due date from your last period, conception date, or IVF transfer date, and see how far along you are.
Ovulation Calculator
Predict your ovulation date and fertile window based on your last period and cycle length to help plan or prevent pregnancy.
Conception Calculator
Estimate when conception likely occurred based on your due date or your baby's birth date, including the probable fertile window.
Period Calculator
Predict your next period dates, track your cycle day, and estimate upcoming ovulation based on your last period and average cycle length.
Other
Macro Calculator
Calculate your daily macronutrient targets for protein, carbs, and fat based on your body stats, activity level, goal, and preferred diet style.
Carbohydrate Calculator
Find out how many grams of carbohydrates you need each day based on your calorie needs, activity level, and the carb percentage you prefer.
Protein Calculator
Find your optimal daily protein intake based on body weight, activity level, and fitness goal. See the per-meal breakdown and calorie contribution.
Fat Intake Calculator
Calculate your daily fat intake in grams based on your calorie needs, activity level, and the fat percentage you choose. Includes a saturated fat limit.
TDEE Calculator
Estimate your Total Daily Energy Expenditure from your body stats and activity level. See your BMR, activity calories, and calorie targets for weight loss or gain.
GFR Calculator
Estimate your Glomerular Filtration Rate (eGFR) using the CKD-EPI 2021 equation. See your kidney function stage and what it means for your health.
Body Type Calculator
Determine your body frame size (small, medium, or large) from your height and wrist circumference. Frame size helps interpret ideal weight ranges.
Body Surface Area Calculator
Calculate your body surface area (BSA) using the Mosteller, Du Bois, or Haycock formula. BSA is used in medicine for drug dosing and clinical assessments.
BAC Calculator
Estimate your Blood Alcohol Content using the Widmark formula. See your impairment level, equivalent standard drinks, and time until sober. This is an estimate only, never a basis for driving decisions.