Health & Fitness Calculators
Good health decisions start with good data. Our 35 health and fitness calculators give you the numbers behind weight management, nutrition, exercise performance, and reproductive health. Calculate your BMI against WHO categories, find your daily calorie needs with the TDEE calculator, or build a macro split tailored to your goals. Runners can dial in race pace, lifters can estimate one-rep max, and anyone can check their target heart rate zone. For women planning a family, our ovulation, due date, period, and pregnancy calculators provide cycle and milestone estimates. We also cover hydration needs, sleep timing, blood alcohol content, and body surface area. All tools are evidence-based, free, and private.
Weight & Body Composition
BMI, body fat, ideal weight, and body surface area tools.
BMI Calculator
Calculate Body Mass Index and see your WHO weight category.
Body Fat Calculator
Estimate body fat percentage using body measurements.
Ideal Weight Calculator
Find your ideal weight range using multiple medical formulas.
BMR Calculator
Calculate your Basal Metabolic Rate — calories burned at rest.
Body Surface Area Calculator
Estimate BSA for medical dosing and clinical calculations.
Nutrition & Diet
Calories, macros, protein, carbs, and water intake planning.
Calorie Calculator
Find daily calorie targets for weight loss, gain, or maintenance.
TDEE Calculator
Calculate Total Daily Energy Expenditure based on activity level.
Macro Calculator
Split daily calories into protein, carbs, and fat grams.
Protein Calculator
Determine daily protein needs for your weight and goals.
Carbohydrate Calculator
Calculate daily carbohydrate requirements for your activity level.
Water Intake Calculator
Find how much water you should drink daily based on weight and activity.
Exercise & Performance
Running pace, calories burned, one-rep max, and heart rate zones.
Calories Burned Calculator
Estimate calories burned during exercise by type and duration.
Pace Calculator
Calculate running or walking pace, speed, and finish time.
One Rep Max Calculator
Estimate your 1RM from submaximal lifting performance.
Target Heart Rate Calculator
Find your optimal heart rate zone for fat burn or cardio.
Women's Health
Ovulation, pregnancy, period tracking, and weight gain during pregnancy.
Ovulation Calculator
Estimate your fertile window based on your cycle length.
Due Date Calculator
Estimate your baby's expected delivery date.
Period Calculator
Predict your next period and track cycle regularity.
Pregnancy Calculator
Track current week, trimester, and key pregnancy milestones.
Pregnancy Weight Gain Calculator
See recommended weight gain range by trimester and pre-pregnancy BMI.
Lifestyle
Sleep timing and blood alcohol content.
Sleep Calculator
Find ideal bedtimes and wake times based on sleep cycles.
BAC Calculator
Estimate blood alcohol content based on drinks, weight, and time.
Alcohol Calorie Calculator
Count calories in alcoholic drinks by type and serving size.
Walking Calorie Calculator
Estimate calories burned during walks by pace and distance.
Blood Pressure Calculator
Check your blood pressure reading against clinical categories.
Advanced Fitness & Body
Heart rate zones, VO2 max, lean mass, and body composition tools.
Heart Rate Zone Calculator
Find your five heart rate training zones for optimal workouts.
Waist-to-Hip Ratio Calculator
Assess health risk based on waist and hip measurements.
Lean Body Mass Calculator
Calculate lean body mass excluding body fat.
Army Body Fat Calculator
Estimate body fat using the U.S. Army tape test method.
VO2 Max Calculator
Estimate your maximal oxygen uptake for cardio fitness assessment.
Bra Size Calculator
Find your correct bra size from band and bust measurements.
Nutrition Plans
Keto, fasting, and specialized diet calculators.
Keto Calculator
Calculate macros for a ketogenic diet based on your goals.
Fasting Calculator
Plan intermittent fasting schedules and track fasting windows.
Pregnancy & Baby
IVF due date and baby growth tracking.
Frequently Asked Questions
What health calculators do I need for weight loss?
Start with a TDEE (Total Daily Energy Expenditure) calculator to find your maintenance calories, then use the calorie calculator to set a deficit. The macro calculator helps divide calories into protein, carbs, and fat. Track progress with the BMI calculator and body fat calculator. Together these tools give you a data-driven weight loss plan.
How accurate is a BMI calculator?
BMI is a useful screening tool that correlates weight with height, but it does not distinguish between muscle and fat. Athletes or muscular individuals may show a high BMI despite low body fat. For a more complete picture, combine BMI with body fat percentage, waist circumference, or body surface area measurements.
What is TDEE and why does it matter?
TDEE (Total Daily Energy Expenditure) is the total number of calories you burn per day including basal metabolism, physical activity, and the thermic effect of food. Knowing your TDEE lets you set accurate calorie targets — eat below it to lose weight, at it to maintain, or above it to gain. Our calculator uses the Mifflin-St Jeor equation with your activity level.
How do pregnancy and ovulation calculators work?
The ovulation calculator estimates your fertile window based on your average cycle length and last period date. The due date calculator estimates your expected delivery date, typically 280 days (40 weeks) from the first day of your last menstrual period. The pregnancy calculator tracks your current week and trimester. These are estimates — always confirm with your healthcare provider.