Free Fitness Calculators - BMI, TDEE, Macros, Body Fat and More
37+ science-backed calculators and AI-powered fitness tools. Peer-reviewed formulas from WHO, CDC, ACSM, and ISSN. Free forever, no signup required.
Most Popular Fitness Calculators
AI-Powered Fitness Tools - Free, No Signup
The only free fitness calculator platform with built-in AI workout and meal plan generators. Generate a complete personalized plan in seconds. No account. No paywall.
AI Workout Plan Generator
Generate a complete personalized training plan based on your goals, equipment, and available days.
Generate Workout PlanAI Meal Plan Generator
Get a custom weekly meal plan matched to your calorie targets, dietary preferences, and macros.
Generate Meal PlanSupplement Stack Builder
Build a personalized supplement stack based on your goals, budget, and training style.
Build Your StackFree Online Fitness and Health Calculators
37+ tools organized by category. Find exactly what you need.
Body Composition Calculators
7 toolsMeasure and track body fat percentage, lean body mass, BMI, and ideal weight using the US Navy method, BMI classification, and army standards. WHO and CDC guidelines.
Daily calorie needs, TDEE, macro tracking, protein targets, creatine dosing, and intermittent fasting schedules. All ACSM and ISSN reviewed.
One rep max for bench press, squat, and deadlift. Compare lifts against strength standards and calculate your Wilks score. Epley and Brzycki formulas.
Training pace, target heart rate zones, VO2 max, and step-to-calorie conversion. ACSM exercise testing guidelines.
Wellness Calculators
3 toolsDaily water intake, optimal bedtime using 90-minute sleep cycles, and healthy weight range with four validated formulas. Reviewed by a nutritional therapist.
Free AI Fitness Tools
3 toolsAI-powered tools found nowhere else free. Personalized workout plans, custom meal plans, and supplement stacks in seconds. No account, no subscription.
Fitness and Nutrition Guides
How to Break a Weight Loss Plateau: Adjusting Your Calories When Progress Stops
Your deficit stopped working. Here is why weight loss plateaus happen and the three evidence-based strategies to break through them.
How to Read Your AI Meal Plan: Making the Most of a Generated Diet
AI meal plan generators create personalized nutrition plans in seconds. Here is how to evaluate the output and make it work for your real life.
Body Type Quiz: Ectomorph, Mesomorph, or Endomorph - Does It Actually Matter?
Somatotype theory has weak scientific support as a rigid system. But body type categories are still useful as loose guidelines. Here is the honest take.
Frequently Asked Questions About Fitness Calculators
The Mifflin-St Jeor equation is the most validated formula for BMR and TDEE estimation according to research published in the American Journal of Clinical Nutrition (Mifflin et al., 1990). Our TDEE Calculator uses this as its primary calculation method and is reviewed by a registered nutritional therapist.
Use our free TDEE Calculator. Enter your age, weight, height, and activity level to get your maintenance calories. To lose weight, eat 300 to 500 calories below that number per day. This creates a safe, sustainable deficit of 0.5 to 1 pound of fat loss per week.
According to the World Health Organization, a BMI between 18.5 and 24.9 is classified as normal weight for adults. BMI is a screening tool and does not account for muscle mass or body composition. Use our Body Fat Calculator alongside BMI for a more complete picture of your health.
Research from the International Society of Sports Nutrition recommends 1.6 to 2.2 grams of protein per kilogram of bodyweight for people engaged in regular resistance training. Our Protein Calculator gives you a personalized daily target based on your weight, activity level, and fitness goals.
Formula-based calculators are accurate within 10 to 15 percent for most people. All formulas on FitnessProGuide are derived from peer-reviewed research and produce reliable starting points. You should adjust your targets based on real results over 2 to 4 weeks.
A one rep max (1RM) calculator estimates the maximum weight you can lift for one repetition on any exercise. Enter a weight you can lift for multiple reps and our calculator uses the Epley and Brzycki formulas to estimate your 1RM safely, without the injury risk of testing it directly.
No. Every tool on FitnessProGuide is completely free with no account, no signup, and no email address required. All calculations run in your browser. We do not store your personal data.
Every calculator on FitnessProGuide uses formulas sourced from peer-reviewed research and official health body guidelines including WHO, CDC, ACSM, ISSN, and ACOG. Each calculator page cites its primary academic source. See our full Methodology page for the complete reference list.
Why Choose FitnessProGuide
Science-Backed Calculators
Whether you need a BMI calculator, a TDEE calculator, a macro calculator, or a body fat calculator, every tool is free and requires no signup. All formulas are sourced from peer-reviewed research and reviewed by Linda Murray, RNT.
Strength and Cardio Tools
Our one rep max calculator, bench press calculator, squat calculator, and deadlift calculator help you track progress. Compare lifts against strength standards. For cardio, use the running pace calculator, heart rate calculator, and VO2 max calculator.
AI-Powered Planning
Three AI tools available nowhere else for free: an AI workout plan generator, an AI meal plan generator, and a supplement stack builder. Generate a complete personalized plan in seconds. No subscription, no account, completely free.