Both equations estimate your Basal Metabolic Rate (BMR), but scientific studies show one consistently outperforms the other for modern metabolic accuracy.
The Mifflin-St Jeor equation is more accurate for most modern adults. Validated by the Academy of Nutrition and Dietetics, Mifflin-St Jeor estimates BMR within ±10% of measured indirect calorimetry in 82% of individuals, compared to 68% for the revised Harris-Benedict formula. Harris-Benedict tends to overestimate BMR by 5% to 15% in sedentary individuals.
| Feature / Metric | Mifflin-St Jeor (1990) | Harris-Benedict (1919/1984) |
|---|---|---|
| Clinical Accuracy | High (±10% accuracy in 82% of adults) | Moderate (overestimates BMR by 5–15%) |
| Variables Used | Weight (kg), Height (cm), Age (yrs), Sex | Weight (kg), Height (cm), Age (yrs), Sex |
| Best Suited For | General population, weight loss planning, sedentary workers | Highly active individuals, endurance athletes |
| Clinical Recommendation | Recommended by Academy of Nutrition & Dietetics | Historical benchmark, still widely used in fitness apps |
Use HealthCalcPro's free Calorie Calculator powered by the Mifflin-St Jeor formula for exact TDEE results.