# Metabolic rate | BMR | RMR

What is BMR and RMR? For it we first have to understand the Metabolic rate. ##### Metabolic rate:

The number of calories you would burn off in a day while at rest.

So, not moving around or being active.

In the fitness community there are two popular formulas to calculate this:

• 1) BMR: basal metabolic rate:

BMR is taken after eight hours of sleep and twelve hours of fasting.

• 2) RMR: resting metabolic rate:

RMR is taken under fewer restrictions and has been shown to be statistically more accurate

let’s look at a couple of examples,

Here we have A (Male) and B (Female) and their metrics are shown here,

A (Male) = 44 years old, 5 foot 8 inches, and weighs 160 pounds.

B (Female) = 33 years old, 5 foot 4 inches, and weighs 126 pounds.

The RMR equation,

Males = (4.55 x Weight in pounds) + (15.88 x Height in inches) – (5 x Age) + 5

Females = (4.55 x Weight in pounds) + (15.88 x Height in inches) – (5 x Age) – 161

when we plug in A and B’s numbers,

A= [ (4.55 x 160) + (15.88 x 68) – (5 x 44) +5 = 1592.84 Calories/Day ]

B= [ (4.55 x 126) + (15.88 x 64) – (5 x 33) – 161 = 1263.62 Calories/Day ]

We see that A’s RMR is 1592.84 calories per day.

And B’s is 1263.62 calories per day.

So after rounding up this tells us that,

If “A” and “B” were to sit around all day they would need 1583 and 1264 calories per day to maintain their weights.

We know that neither A nor B are going to sit around all day so there’s a multiplication factor that we must use next.

It’s based on each of their lifestyles.

The factor is as follows:

 1.200 – Sedentary Lifestyle (Little to                                           no Exercise) 1.375 – Lightly Active (Light Exercise                                       1-3 Days/Week) 1.550 – Moderately Active (Moderate                      Exercise 3-5 Days/Week) 1.725 – Very Active (Hard Exercise                                       6-7 Days/Week) 1.900 – Extra Active (Very Active Very                 Hard Exercise/Physical Job)
let’s say the A is very sanitary ( which is a Sedentary Lifestyle (Little to no Exercise),

So if we multiply his RMR by 1.2 we have 1911.6 calories/day

Now, Samantha’s in the very active category so,

We need to multiply her RMR by 1.725 we get 2180.4 Calories/Day so based on these calculations.

“A” can consume 1912 per day to maintain his current weight.

And “B” can consume 2180 Calories/Day to maintain her currently. Now you can use the RMR equation and lifestyle multiplication factor to calculate your baseline.

##### Drawbacks:

Few things I need to mention first, this and any other formula used to calculate your metabolic rate is just an estimate.

There is a margin for error.
Muscle mass is very important,

let’s look at Kyle and Jack who both weigh the same.

However, Jack has much more muscle mass than Kyle.

Since muscle burns more calories in fat, Jack will have a higher metabolic rate.
The formula does not account for this situation