Free Fitness Calculators
Use our free fitness calculators to estimate BMI, BMR, TDEE, body fat, calories, macros, running pace, 1RM, heart rate zones and more. Get quick, practical estimates to support your fitness goals.
⚖️ Body & Weight
BMI Calculator
Calculate your Body Mass Index (BMI) using your height and weight. See the general BMI category associated with your result.
BMR Calculator
Estimate your Basal Metabolic Rate (BMR), the approximate calories your body needs at rest to support basic functions.
TDEE Calculator
Estimate your Total Daily Energy Expenditure (TDEE), or the approximate calories you burn each day based on your activity level.
Ideal Weight Calculator
Get an estimated healthy weight range based on your height and basic personal information.
Body Fat Calculator
Estimate your body fat percentage using basic body measurements. Results are estimates rather than clinical measurements.
Lean Body Mass
Estimate lean body mass from weight and body fat.
🥗 Nutrition & Calories
Calorie Deficit Calculator
Estimate a daily calorie target for weight loss based on your estimated energy needs and selected calorie deficit.
Macro Calculator
Estimate daily protein, carbohydrate and fat targets based on your calorie needs and fitness goal.
Activity Calories
Estimate calories burned during common activities.
🏋️ Exercise & Performance
Steps to Miles
Convert steps into an estimated walking distance.
1 Rep Max Calculator
Estimate your one-repetition maximum (1RM) from the weight and repetitions you can perform in an exercise.
Heart Rate Zones
Estimate five training zones based on age.
🏃 Running & Walking
Running Pace Calculator
Calculate running pace, speed, distance or estimated finish time for training sessions and races.
Steps Calories
Estimate calories burned from daily steps.
Weight Loss Calorie Target
Estimate a daily calorie target from maintenance calories.
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Free Fitness Calculators for Your Goals
MariaFitness provides free fitness calculators to help you understand common fitness, nutrition and training measurements. Use the tools above to estimate BMI, BMR, TDEE, body fat, calorie needs, macronutrients, running pace, strength performance and more.
How These Fitness Calculators Work
Each calculator uses the information you enter with a commonly used formula or estimation method. Because calorie needs, body composition and exercise performance vary between individuals, the results should be treated as useful estimates rather than exact measurements.
For more consistent results, use accurate measurements and update your information when your body weight, activity level or fitness goals change.
Frequently Asked Questions
Are the MariaFitness calculators free?
Yes. All calculators on this page are free to use and are designed to provide quick fitness and nutrition estimates.
Are fitness calculator results accurate?
Calculator results are estimates. Formulas use general assumptions, while individual calorie needs, body composition and exercise performance can vary from person to person.
What is the difference between BMR and TDEE?
BMR estimates the energy your body needs at rest. TDEE estimates your total daily energy expenditure by taking activity into account.
Which calculator can help with weight loss?
The Calorie Deficit and Weight Loss Calorie Target calculators can provide starting-point estimates. Your actual needs can vary, so monitor progress and adjust appropriately.
Can I use these calculators for workout planning?
Yes. Tools such as the 1 Rep Max, Heart Rate Zones, Running Pace and Activity Calories calculators can provide useful training estimates.
Should these calculator results be treated as medical advice?
No. These tools are intended for general informational and educational use. If you need personalized medical, nutrition or exercise advice, consult a qualified professional.