Now that counting calories has become second nature, you need to find out what your daily caloric allowance actually is. Grab a pen and paper. Oh wait, you have your handy notebook from calorie counting available! How efficient. To calculate your daily caloric allowance, we’ll need to calculate your BMR. *Warning: this post is a bit mathematical but don’t worry. Google can be your calculator.

First off…

What is BMR? BMR stands for basal metabolic rate. BMR is the amount of energy, measured in calories, used by the body if it remains asleep in bed all day. It is one of the largest factors in determining overall metabolic rate and how many calories you will need to maintain, lose or gain weight. There are a bunch of factors that determine BMR but I won’t go into that.

How does the BMR equation work? I know it sounds like calculus but believe me, it’s not. The first step is to find out how many calories you burn in a day. This is called your Total Daily Energy Expenditure (TDEE).

TDEE can be seen as the number of calories your body uses in a 24 hour period. More importantly, it is known as the maintenance level. Knowing your TDEE will give you a reference point since you will know what your body requires to stay at a certain weight.

Calculating Your BMR: The Harris-Benedict Formula Big words, big formula, easy solving. The formula uses height, weight, age and sex to determine BMR. The formula does not take into account lean body mass, so the result will be less accurate for those who are extremely muscular (not me) or extremely overfat (why, hello!)

Men: 66 + (13.7 x wt in kg) + (5 x ht in cm) – (6.8 x age in years)

Women: 655 + (9.6 x wt in kg) + (1.8 x ht in cm) – (4.7 x age in years)

Oh hey, I know what the Americans are thinking. Kilograms and centimeters?! Oh no! Don’t worry. Google will tell you.

For me, I type in 204 pounds in kg and I get 92.53. Brilliant!

Same thing for centimeters. I would convert your feet to inches however, and give your height in total inches. There’s 12 inches in a foot. I’m 5 feet 6 inches, or 66 inches. In Google, I typed 66 inches to cm and got 167.64 cm.

Age in years is 23.

Now that all the variables are present, I plug the information into the woman equation: 655 + (9.6 x 92.53) + (1.8 x 167.64) – (4.7 x 23)

This is where your calculator may come in handy, or if you’re like me, I copy and pasted the equation into Google. The result: 1736.94. For the sake of using nice round numbers, let’s just say 1737. This means that if my body was sleeping all day, no movement, no eating, no nothing, it would burn 1737 calories.

Now that you know BMR, what do you do? Time to calculate your TDEE. There’s an activity multiplier that you use.

Sedentary = BMR x 1.2 (little or no exercise)
Lightly active = BMR x 1.375 (light exercise, 1-3 days/week)
Mod. active = BMR x 1.55 (moderate exercise, 3-5 days/week)
Very active = BMR x 1.725 (hard exercise, 6-7 days/week)
Extreme active = BMR x 1.9 (hard daily exercise, 2 times daily training)

I think only people like Michael Phelps would use the last equation. For me, I decided to be modest and selected the moderately active even though I workout like a beast in the gym. Why? Because I figure it’s better safe than sorry.

So, my TDEE = 1.55 x 1737. Plug into Google and I got: 2692.35 We’ll round that to 2692. That means that I will maintain my weight of 204 pounds if I eat 2692 calories a day. Well damn, that’s a lot of calories!

Whew, now that all the math is finished, what next? Now that you know what you need to maintain, you can adjust accordingly. A negative calorie balance is required to lose weight. It doesn’t matter what you eat. If you eat more than you expend, you just won’t lose fat. You have to be in a calorie deficit in order to burn fat. This forces your body to use stored body fat in order to make up for the deficit.

Remember when I said 3500 calories equals one pound? If you create a 3500-calorie deficit in a week through diet and exercise, you will lose one pound.

A good place to start… is to reduce calories by 15-20% below TDEE. So for me, 2692 x 0.2 gives me 538.4. Subtract that from 2692 (2692 – 538.4) and I get 2153.6. Right now, I’m averaging roughly 1500 calories a day, which gives me a significant amount of deficit and probably explains why I lost 9 pounds in 2 weeks.

BUT, how much is too low? The American College of Sports Medicine recommends that calorie levels never drop below 1200 per day for women and 1800 per day for men.

Wrapping it up… Now that you have an overall idea of BMR and how many calories your body roughly requires every day, you can adjust your caloric intake accordingly. Remember to not go too low. Starving your body won’t help you lose fat. It’ll only create a starvation response in which your body actually RETAINS the fat for fear of death. The best way to lose weight is by decreasing caloric consumption while increasing physical activity.

Is it tiring? Yes. Worth it? Definitely.