The basal metabolic rate is a measure of energy (calories) used for essential life functions this is called basal metabolic rate (BMR).

Basal metabolism includes very function including most involuntary functions your body does to support life:

• Breathing
• Blood circulation
• Body temperature regulation
• Nervous system…

Still not the extra energy needed for any additional physical activity such as gym exercise.

In other words…

If you laid in bed all day doing nothing else, you would need to eat at least the number of calories roughly equal to your BMR in order to maintain your normal body functions.

Basal metabolism consumes from 60 to 70% of body’s total daily calories expenditure.

What is RMR?

Resting Metabolic Rate (RMR) is equivalent to BMR, it is measured under less strict conditions.

BMR is usually measured in special lab conditions where even room temperature has to be exact. RMR is BMR value adjusted for the daily life environment…

RMR values are about 15% higher than the BMR values.

In your diet calculations, you can safely use RMR instead of scientifically precise BMR.