Fitness Calculators
Welcome to the fitness & health calculator hub. Whether you’re tracking your BMI, figuring out your daily calorie needs, or estimating body fat percentage, these free tools give you clear, science-based answers in seconds — no sign-up, no email, no fine print.
31 free calculators
BMI & Weight
Anorexic BMI Calculator
Look up standard BMI classification bands, including the clinically underweight range, for reference.
Use calculator →Army Body Fat Calculator
Estimate body fat percentage using the U.S. Army circumference-based method.
Use calculator →BMI Calculator
Calculate your Body Mass Index and see your weight category.
Use calculator →Body Fat Calculator
Estimate body fat percentage using the U.S. Navy circumference method.
Use calculator →Body Type Calculator
Estimate your body type (somatotype) from your measurements.
Use calculator →Healthy Weight Calculator
Find the healthy weight range for your height, based on standard BMI cut-offs.
Use calculator →Ideal Weight Calculator
Estimate your ideal body weight using several established formulas.
Use calculator →Lean Body Mass Calculator
Estimate your lean body mass (fat-free mass) using the Boer formula.
Use calculator →Overweight Calculator
Check whether your weight falls into the overweight BMI range and see how much is above the healthy range.
Use calculator →Fitness & Performance
Calories Burned Calculator
Estimate calories burned during an activity using MET values.
Use calculator →One Rep Max Calculator
Estimate your one-rep max (1RM) using the Epley formula.
Use calculator →Pace Calculator
Calculate running pace, time or distance - given the other two.
Use calculator →Target Heart Rate Calculator
Find your target heart rate training zones using the Karvonen method.
Use calculator →Health & Medical
BAC Calculator
Estimate blood alcohol concentration using the Widmark formula. For education only.
Use calculator →Body Surface Area Calculator
Estimate body surface area (BSA) using the Du Bois formula.
Use calculator →GFR Calculator
Estimate glomerular filtration rate (kidney function) using the CKD-EPI formula.
Use calculator →Metabolism
Nutrition
Calorie Calculator
Estimate your daily calorie needs to maintain, lose or gain weight.
Use calculator →Carbohydrate Calculator
Estimate your recommended daily carbohydrate intake.
Use calculator →Fat Intake Calculator
Estimate your recommended daily fat intake based on total calories.
Use calculator →Macro Calculator
Get personalized protein, carb and fat targets based on your calories.
Use calculator →Protein Calculator
Estimate your recommended daily protein intake based on weight and activity.
Use calculator →Weight Watcher Points Calculator
Estimate a SmartPoints-style value for a food based on its nutrition facts.
Use calculator →Pregnancy & Cycle
Conception Calculator
Estimate your most likely conception window.
Use calculator →Due Date Calculator
Estimate your baby's due date from your last menstrual period or conception date.
Use calculator →Ovulation Calculator
Predict your next fertile window and ovulation day.
Use calculator →Period Calculator
Predict your next few period start dates based on your cycle history.
Use calculator →Pregnancy Calculator
Estimate your due date and current week of pregnancy from your last period.
Use calculator →Pregnancy Conception Calculator
Estimate your likely conception date from your due date or last period.
Use calculator →Pregnancy Weight Gain Calculator
See the recommended healthy weight gain range for your pregnancy based on pre-pregnancy BMI.
Use calculator →Complete Guide to Fitness Calculators
How to use our health tools well — and what your results really mean.
How to Use Our Fitness & Health Calculators
You don't need a medical degree or a fitness app subscription to get useful answers here. Each tool follows the same simple flow:
- Pick your calculator. Start with the one closest to your goal — weight, calories, body fat, or performance.
- Enter your numbers. Height, weight, age, sex, and activity level (specific fields vary by tool).
- Calculate. Results appear instantly, with a clear number and context on what it means.
- Track and adjust. Recheck weekly or monthly as your weight or fitness level changes to see your progress.
That's it. No account, no downloads, no data stored. Your numbers stay on your device.
Frequently Asked Questions
Are these fitness calculators really free?
Yes — every calculator is 100% free, with unlimited use and no sign-up required.
How accurate is the BMI calculator?
It uses the standard WHO formula (weight ÷ height²) and is accurate for most adults. BMI doesn’t account for muscle mass, so athletes may see skewed results — a body fat calculator gives a fuller picture.
Do the calculators work on mobile?
Absolutely. All tools are fully responsive and work on phones, tablets, and desktops.
What's the difference between BMR and TDEE?
BMR is the calories your body burns at complete rest. TDEE adds your activity level on top of BMR to give your total daily calorie burn — the number most people use for weight loss or gain planning.
Should I trust these calculators over a doctor's advice?
These tools give solid estimates for general planning, but they’re not a substitute for medical advice. For health conditions, pregnancy, or specific medical concerns, talk to a doctor or registered dietitian.
Popular fitness & health calculators
Start with the tools visitors use most.