Advanced Mifflin-St Jeor Equation Calculator & TDEE Planner

Advanced Mifflin-St Jeor Equation Calculator

Determine your precise BMR, TDEE, and customized weight management calorie targets using the gold-standard clinical formula.

Metabolic Target Outputs

Basal Metabolic Rate (BMR) -- kcal
Total Daily Energy Expenditure -- kcal
Target Goal Recommendation --

Caloric Target Breakdown Visualizer

Extreme Loss
Loss
Maintenance
Gain
1,000 kcal 2,000 kcal 3,000 kcal 4,000+ kcal
Current Maintenance TDEE: -- kcal/day

The Clinical Precision of the Mifflin-St Jeor Equation

Introduced in 1990 by Dr. M.D. Mifflin and Dr. S.T. St Jeor, this formula replaced older standards like the Harris-Benedict equation as the benchmark for estimating resting energy expenditure. Clinical studies consistently demonstrate that it yields the most accurate predictive results for contemporary populations.

BMR vs. TDEE: Understanding Your Energy Needs

  • Basal Metabolic Rate (BMR): The baseline energy your organs require to stay alive at complete rest.
  • Total Daily Energy Expenditure (TDEE): BMR multiplied by your physical activity level (PAL), accounting for digestion, daily movement, and structured exercise.

Applying Calorie Targets for Body Composition Goals

To achieve sustainable weight loss, creating a moderate deficit of 300 to 500 calories below your TDEE ensures fat loss while preserving lean muscle mass. Conversely, fueling a slight surplus above TDEE supports muscle hypertrophy during resistance training programs.