Key Takeaways
- The Mifflin-St Jeor equation (1990) is considered the most accurate REE prediction for the general population.[1]
- REE typically accounts for 60–75% of total daily energy expenditure, making it the largest component of calorie burn.[2]
- Formulas can differ by 100–300 kcal/day depending on body composition and age — comparing multiple estimates provides a realistic range.[3]
How the Formulas Work
Mifflin-St Jeor: 10×weight(kg) + 6.25×height(cm) − 5×age + s
(s = +5 for males, −161 for females)
Cunningham: 500 + 22 × lean body mass(kg)
(requires body fat %)
The Cunningham formula is particularly accurate for athletic individuals with known body composition, as it directly accounts for lean mass rather than total body weight.[3]
To calculate your total daily energy expenditure including activity, use the AMR (Active Metabolic Rate) Calculator.
Limitations and Important Notes
- All formulas are population-derived estimates. Individual REE can vary ±10% from predicted values.
- The Harris-Benedict equation tends to overestimate REE in individuals with obesity.
- REE decreases with age and is affected by thyroid function, body temperature, and other physiological factors not captured by these equations.
- This tool is for informational and journaling purposes only. It does not constitute personalized advice.
Frequently Asked Questions
Sources & References
- Comparison of predictive equations for resting metabolic rate. Various. PMC (2023)
- A new predictive equation for resting energy expenditure in healthy individuals. Mifflin MD, St Jeor ST, et al.. Am J Clin Nutr (1990)
- Body composition and resting metabolic rate. Cunningham JJ. Am J Clin Nutr (1991)

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Certified Personal Trainer & Sports Nutritionist from the National Academy of Sports Medicine
This tool is for informational and journaling purposes only.
I am NOT a doctor.