These two terms are used interchangeably, although they are not technically the same. Resting metabolic rate is really what most lay people mean when they say basal metabolic rate, and I talk here only about resting metabolic rate (RMR). Basal metabolic rate is a precise calculation with a precise definition; RMR is close enough for practical purposes.

Resting metabolic rate is the energy required by an animal to stay alive with no activity. Therefore, your real metabolic rate is always significantly higher than your RMR. Calculating RMR is a very useful first step in calculating your real metabolic rate.

Your Resting Metabolic Rate (RMR) is one of the main contributing components of energy expenditure (around 70%).

The latest research indicates there is a low variance in RESTING metabolic rate [(RMR)] between individuals who have the same values for the key variables. That is, given someone’s age, their fat free mass, their height and their sex, the formulas are accurate.