Working with Calories, part 1: Just how many Calories do I burn each day?

It’s the beginning of the year and everyone is taking a good hard look at what they are eating and what they need to do to lose unwanted pounds.

With that in mind, I find it useful to at least have a rough idea of how many calories you are burning each day.

Now I know many people do not want to count calories, and thats cool I find I only do it for 2-3 weeks a couple of times per year at most.  But knowing how many calories you are burning can be useful.

So lets get straight to it.

We can get an approximation of your daily calorie expenditure using the 'Harris Benedict' formula, a 2 stage calculation that will tell you how many calories you are burning each day.


Part 1; Calculating BMR
Your BMR (Basal metabolic rate) is the number of calories you burn every 24 hours if you remained in bed.

It's a bit lengthy but here are the calculations;

In order to calculate BMR for Women;

Metric     BMR= 655.1 + (9.563 x wgt in kg) + (1.850 x hgt in cm) - (4.676 x age)

Imperial  BMR= 655.1 + (4.35 x wgt in Ibs) + (4.7 x hgt inches) - (4.7 x age)


To calculate BMR for Men;
Metric  BMR= 66.5 + (13.75 x wgt in Kg) + (5.003 x hgt in cm) - (6.775 x age)

Imperial BMR= 66 + (6.2 x wgt in Ibs) + (12.7 x hgt in inches) - (6.76 x age)

Let's quickly run through it using me as an example;

BMR= 66.5 + (13.75 x 80Kg) + (5.003 x 172cm) - (6.775 x 39)
           66.5  +    1100             +         861             -        264      = 1763.5kcal/day

So there we go, if I didn't move from my bed I'm still burning 1763.5kcal per day.


Now this is just your BMR and in no way accounts for your day to day moving around.  When we factor in your activity as well we create your TDEE-Total daily Energy Expenditure.

Part 2; Calculating your TDEE

Now we have our BMR we must consider our activity factor using the scale below;

• If you are sedentary (little or no exercise) BMR x 1.2 = TDEE
• Light active (sports/ exercise 1 - 3 times per week) BMR x 1.375= TDEE
• Moderately active (sports/exercise 3 - 5 times per week) BMR x 1.55= TDEE
• Very active (hard exercise/sport 6 - 7 times per week) BMR x 1.725= TDEE
• Extra active (Exercise 2 x day/physical job) BMR x 1.9 = TDEE

Once again using me as the example;

BMR = 1763.5 x 1.55 (moderately active)=2733kcal

So there we go, now that you have worked through that you should have your Total daily Calorie expenditure.  Do keep in mind though, this is an approximate figure not an absolute, but for our intent and purposes it works just fine.

Now we have this information what do we do with it?

Keep a look out for that in my next post where I will show you how to use the above results and apply it to achieve desired weight change.