How to Calculate Calorie Burn Ratio Rigorously?

Calculate Calorie Burn Ratio
Editor's Note: This article has been recently updated with latest information and research studies.

The golden rule for weight loss* is to burn more calories than you consume. The same rules apply to people who want to get ripped and sexy body. Some people count calories in food, download fitness trackers that automatically show how many calories you burn on a daily basis, the entire idea of calorie burn is poorly understood. Your success in any fitness endeavor, weight loss* or any other, depends on the thorough understanding of all aspects of the process. Did you know you can calculate how many calories you burn without a smartphone or display on gym machines? It’s very easy to do it yourself (and incredibly fun). This article will show you how to calculate a number of calories you burn during the day. Let’s start!

Calories Explained

You talk about calories every day, read about them, try to implement different tips to burn them, but would you be able to explain what calories are and how our body uses them? In fact, most people wouldn’t mostly because internet sources on this topic don’t try to explain the subject. That’s about to change now.

The easiest definition would be that a calorie is a unit of energy. When eating, you’re fueling the body with energy that comes in the form of calories. The organism uses that energy flow for exercise and other vital functions such as breathing. You also need the energy to be productive at work, alert at the class, and so on.

Calories represent the amount of energy it takes for the temperature of one gram of water to increase* by one degree Celsius (1.8°F). There are only two ways your body deals with the calories you consume via food; store it or burn it. Of course, the latter option is more beneficial for both your health and waistline. That’s why in order to lose* weight you have to burn more calories than you consume. In case, you burn and consume the same amount of calories; your weight won’t change. And naturally, if you consume more calories than you burn, you will gain weight. As you can see, calories are simple, but how to know how to burn them? There are different methods you can use.

Calories Explained

Calculating Calorie Burn

In order to calculate how many calories you spend, you have to know the following components:

  • BMR (Basal Metabolic Rate) – a number of calories the body burns* at rest. BMR represents 65% of total calorie burn, on average
  • Activity level – the quantity of calories you burn when the body is in motion. Typically, the more active you are, the more calories you’ll burn. This factor accounts for 20% of total calorie burn
  • Thermic effect of food – even digesting the food requires energy. This aspect represents 10% of total calorie burn

Below, you can see two practical methods to calculate the calorie burn.

Calorie Burn

Method #1: Harris Benedict

Most calorie burners you find on the internet use this method. This technique takes into account your age, weight, height, and gender to calculate the BMR. In order to determine the activity level, you have to multiply BMR with the Activity Multiplier, which is displayed below. There is no need to make individual calculations regarding the thermic effect of food because it’s already included in the BMR calculation. The equations are below:

BMR for men: 66 + (6.23 x weight in pounds) + (12.7 x height in inches) – (6.8 x age)

BMR for women: 655 + (4.35 x weight in pounds) + (4.7 x height in inches) – (4.7 x age)

To calculate calorie burn with this method you just have to: BMR x Activity Multiplier.

You probably notice that this technique doesn’t consider the body composition even though individuals with more muscle are more metabolically active and thereby burn more calories. Although the method isn’t perfect, it’s quite accurate and poses as the simplest ways to start monitoring your own calorie burn.

calculate calorie burn

Method #2: Katch & McArdle

This approach relies on the body composition to calculate BMR, and it’s even more precise than the previous method. Here, you use the same Activity Multiplier as in the previous method. Below, you can see equations for this technique:

BMR (Men + Women) = 370 + (21.6 x lean mass in kg)

Lean mass: weight in kg – (weight in kg x body fat %)

Since first two methods use the same Activity Multiplier, here it is:

  • Little or no exercise, desk job: 1.2 x BMR
  • Light exercise, sports 1 to 3 times per week: 1.375 x BMR
  • Moderate exercise, sports 3 to 5 times per week: 1.55 x BMR
  • Heavy exercise, sports 6 to 7 times per week: 1725 x BMR

See Also: Calculate Yourself: How Much Should You Be Eating?


Understanding how calories work and being able to calculate how many of them, you burn on average helps you create an effective plan to lose* weight or get a ripped body. In this article, you’ve seen two easy methods to calculate the calorie burn on your own. Naturally, you shouldn’t underestimate the practicality of gadgets and fitness trackers that can also help you achieve your goal.



Take Action: Support Consumer Health Digest by linking to this article from your website

Permalink to this article:

Embed article link: (Click to copy HTML code below):

Reprinting this article:
Non-commercial use OK, cite with clickable link.


Expert Author : Dr. Ahmed Zayed (Consumer Health Digest)

Dr. Ahmed Zayed Helmy holds a baccalaureate of Medicine and Surgery. He has completed his degree in 2011 at the University of Alexandria, Egypt. Dr. Ahmed believes in providing knowledgeable information to readers. Other than his passion for writing, currently he is working as a Plastic surgeon and is doing his masters at Ain shams University.