About SmartFitCalc

SmartFitCalc provides free, accurate, and easy-to-use fitness calculators to help you understand your body's needs and achieve your health goals. Whether you're looking to lose weight, build muscle, or maintain a healthy lifestyle, our tools give you the data you need to succeed.

Our Mission

We believe that everyone deserves access to accurate health and fitness information without barriers. Our mission is to provide scientifically-backed calculators that are:

Accurate

Based on peer-reviewed scientific formulas and validated methods

Private

Your data stays in your browser - we never collect or store your information

Free

100% free to use with no hidden fees or subscriptions

Our Calculators

TDEE Calculator

Calculate your Total Daily Energy Expenditure using the industry-standard Mifflin-St Jeor equation. If you know your body fat percentage, we also use the more accurate Katch-McArdle formula.

Try TDEE Calculator →

Macro Calculator

Get personalized macronutrient recommendations based on your goals. Choose from Balanced, Low Fat, Low Carb/Keto, or High Protein diet templates.

Try Macro Calculator →

Body Fat Calculator

Estimate your body fat percentage using the US Navy Method, a validated formula used by the United States military for fitness assessments.

Try Body Fat Calculator →

Our Methodology

All calculations on SmartFitCalc are based on peer-reviewed scientific research and validated formulas used by healthcare professionals worldwide:

  • Mifflin-St Jeor Equation (1990): Published in the American Journal of Clinical Nutrition, this formula is widely considered the most accurate for estimating BMR in the general population. Studies show it predicts measured resting metabolic rate within 10% for most adults.
  • Katch-McArdle Formula: Provides more accurate results when body fat percentage is known, as it accounts for lean body mass which is the primary driver of metabolism.
  • US Navy Body Fat Formula: Developed and validated by the United States Navy for service member fitness assessments, this circumference-based method correlates well with hydrostatic weighing.
  • BMI Classification: Based on World Health Organization (WHO) international standards for adult body mass index categories.

Evidence-Based Approach

Our calculators regularly undergo review to ensure they reflect current scientific consensus. All formulas are sourced from peer-reviewed publications and validated methodologies used in clinical practice. However, these tools provide estimates only—individual results may vary based on genetics, health conditions, and other factors.

Have Questions?

We'd love to hear from you! Whether you have feedback, suggestions, or questions about our calculators, don't hesitate to reach out.

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