How Many Calories Do I Burn In A Day?

Post edited April 19, 2012

When you’re deciding on your weight loss battle plan, you usually start with the first question being,

How many calories do I burn in a day right now? If it’s a whole crap-load, then I’m not going to work that hard. If it’s hardly anything to begin with, then I’m going to give up now while I still have some dignity.

Mountain Biking Man

This guy looks like he's in the zone and when you do strenuous physical cardio like this, your calories burned during the day is obviously going to be higher.

OK, so that’s more of a joke, but I’ll honestly attest that probably most people that attempt to lose weight, give up just that easily. They see where they are, they see where they want to be, and then they say “Screw it.”

Well, you might be interested to learn that the number of calories that you’re burning each day right now may only need a very small adjustment to result in you losing as much weight as you choose.

And while there are quite a few equations, formulas, and online web applications that will help you to analytically discover your daily caloric burn, I’m going to show you a much simpler way to formulate this answer and how you can use this knowledge to improve your current fat loss efforts.

Calculating Your Daily Calories Burned Depends On Your BMR (Basal Metabolic Rate)

The beginning, middle, and end of this idea of burning calories throughout the day all has to do with your BMR (Basal Metabolic Rate). Your BMR is the rate that determines how many calories you need in order to continue working your basic functions.

These basic functions constitute most of your vital bodily operations like breathing, sleeping, breaking down food, pumping your heart and blood, and even adjusting your internal temperature. That means everyone’s BMR is always working regardless of how fast they claim it is.

Realistically, most people’s BMR runs at about the same pace. Of course their are special cases that’ll break the bell curve like individuals who burn calories abnormally fast and it’s difficult for them to put on weight. (I’m very jealous of those people)

The opposite effect can also occur with strangely slow metabolisms, but for the most part, everyone is in the middle, running at nearly the same pace when you don’t take into account physical activity lifestyle levels. Your physical activities for the day are the other part of this calorie-burning equation.

There Are Just Too Many Factors To Get A Perfectly Accurate Figure (For Your Daily Burn)

Determining how many calories someone burns in a day is insanely complicated because there are almost too many factors and variables to take into account. Ultimately, your daily calories burned is decided by a combination of your BMR (using your current weight) and your daily physical activity.

If you do a quick search, you can find a number of those calories burned calculator site on the web that you can visit to type in all sorts of data about what you did during the day and they’ll spit out a number that may or may not be relatively close.

Here are a few common ones if you’re curious:

Most of those web apps are made with simple javascript that adds up values based on various fitness rules like:

  1. How many calories in a pound? A pound of muscle burns about 6 calories each day.
  2. A pound of fat burns about 2 calories each day.
  3. Walking burns between 80 – 100 calories per mile.
  4. If you’re male, your result should be between 2,000 – 2,400 calories a day.
  5. If you’re female, your result should be between 1,800 – 2,100 calories  a day.

The first 3 rules have enough research to probably be referred to as facts. I’m not so sure about 4 & 5.

But after you take the time to remember everything that you did, try to figure out how many jumping jacks you did, and how many steps you took around the office…it’s almost not worth it after I explain the simple way to get just as close of an estimate.

BMR Equations And Formulas – Complicated, But There’s An Easier Way…

While I do have to give credit to those calorie burning apps for… well… existing…so people can use them, I only hope that they’re loosely based on one of the established BMR equations or formulas instead of just “adding up all the calories”.

I found the followinig information from the BMR wikipedia page, but I’ll go ahead and summarize my findings here for you. And no it’s not just you. Some of these formulas look downright scary, but this is how people began answering the question “how many calories do I burn in a day?”

In 1919, the Harris-Benedict equation became the first fairly accurate attempt at calculating an individual’s BMR. The factors involved are weight (kg), height (cm), and age (years) for this equation.

For Men

For Women

 

 

Later, another equation was created that better took into account active lifestyles of the late 1900s called the Mifflin equation.

The variable ‘s’ is 5 for men and -161 for women.

Then, a formula took a more accurate inclusion of lean body mass versus body fat to calculate our BMR called the Katch-McArdle formula.

LBM stand for Lean Body Mass.

Now, for an imaginary woman who is 55 years old, 130 lbs (59kg), 5’ 6” (168cm) tall, and 30% body fat, these three formulas would produce the following results:

  • Harris – Benedict Equation = 1272 calories
  • Mifflin Equation = 1204 calories
  • Katch-McArdle Formula = 1263 calories

So, for this imaginary woman to maintain her body weight, she needs to consume around 1246 calories each day. That’s what her body demands based on her current stats. (Her stats are also imaginary)

The Simple Formula To Answer “How Many Calories Do I Burn In A Day?”

Now I know that I’ve been dangling a carrot in front of your face up to this point, but now I’ll reveal how you can formulate the answer to your calorie-burning question. A quick, yet somewhat accurate, estimate of your BMR can be done by taking your current weight in lbs and multiplying by 13 or 14.

Yea, it’s really as simple as that. You’re probably looking at the average of the three equation values (1246) and the value from this simpler version (1300) and thinking

Whoa! That’s a lot higher than I expected!

Well, to be perfectly honest, most people don’t have a clue how many calories they consume on a daily basis. They just don’t care and have never bothered to keep any records. I was completely blown away when I found out how many calories I was using in an entire day. But that’s the first step. Once you know what it is that you eat and how active your life really is, you’ll suddenly be faced with the question, “So what are you going to do about it?”

My first suggestion (and something I’ll probably dedicate an entire post to) is to sign up for MyFitnessPal and start tracking everything that you eat all day long. It’s an awesome site that allows you to look up every food that you can possibly imagine. Plus, if you have a smart phone you can download the phone app and use your phone as a bar scan reader to scan the items you’re eating and add the nutritional values right there. Crazy right?!

Your Next Question Is Probably “How Many Calories Should I Eat To Lose Weight?”

Well the simple answer is around 500 calories less than the number you generated. The number of calories that you burn each day is how many calories it takes to maintain your current weight. This is how much energy your body needs in order to continue sustaining at your current weight.

If you increase this amount, you’ll gain weight, and if you decrease this amount, you’ll lose weight. It’s actually that simple. The tricky part is coming up with a good plan to decrease your caloric intake without sending you spiraling into insanity or some sort of eating disorder.

When you decrease your caloric intake, you’re actually creating a calorie deficit. You can, of course, do this with any combination of dieting and/or exercising. Personally, I like to do both for the fastest results. And I’ve found that the quickest and most sustainable way for me to reduce my calories is by fasting two or more times each week. You can learn more about my fasting methods in this post, Tricking Your Metabolism To Burn Stored Fat By Fasting.

My fasting strategies are based from Eat Stop Eat, and I think it’s great because it’s a technique that I don’t really have to think about. With normal dieting, you have to be concerned with portions of every meal, and eating only “healthy foods”, and I just get fed up with it. With fasting, I just cut out calories for a 24-hour span a few times each week, and I lose weight. (And I’m still losing it)

Knowing the answer to “how many calories do I burn in a day” is the first step to losing weight. You need to know where you start before you can even decide where you want to go.

Photo Attribution: tonylanciabeta / Flickr.com

P.S. If you're interested in the diet that I use when I want to get particularly lean, it's Eat Stop Eat. It's very progressive, and probably not like anything you've tried before.