The Harris–Benedict Equation (Original & Revised)
The 1919 BMR equation that started it all — including its 1984 Roza & Shizgal revision, when it's still useful, and why most dietitians have moved on.
The original (1919)
Men: BMR = 66.5 + (13.75 × kg) + (5.003 × cm) − (6.755 × age)
Women: BMR = 655.1 + (9.563 × kg) + (1.850 × cm) − (4.676 × age)
Published by Francis Harris and James Benedict at the Carnegie Institute in 1919, based on indirect calorimetry of 239 subjects.
The Roza–Shizgal revision (1984)
Men: BMR = 88.362 + (13.397 × kg) + (4.799 × cm) − (5.677 × age)
Women: BMR = 447.593 + (9.247 × kg) + (3.098 × cm) − (4.330 × age)
Roza and Shizgal updated the coefficients to better fit modern adults.
Should you use it?
Probably not. Multiple validation studies have shown Harris–Benedict over-predicts BMR by 5–15% in modern populations, particularly in people with higher body fat. The Mifflin–St Jeor equation was developed specifically to replace it and outperforms both versions in head-to-head accuracy trials.
Use Harris–Benedict only when comparing to older clinical data or research that used it as a baseline. For new calculations, default to Mifflin–St Jeor.
Sources
- Harris JA, Benedict FG. A Biometric Study of Basal Metabolism in Man. Carnegie Institute of Washington, 1919.
- Roza AM, Shizgal HM. The Harris Benedict equation reevaluated: resting energy requirements and the body cell mass. Am J Clin Nutr. 1984;40(1):168–82.