What is Basal Metabolic Rate (BMR)?

The Basal Metabolic Rate (BMR) is the amount of energy (calories) your body needs at rest, assuming no activities, to support your organs vital functions. This energy takes more than 60% of your total daily energy.

How does the BMR calculator work?

One of the most accurate formulas to measure your BMR , which this calculator adopts, is the Harris-Benedict formula:


BMR = 66 + (6.3 x body weight in lbs.) + (12.9 x height in inches) – (6.8 x age in years)


BMR = 655 + (4.3 x weight in lbs.) + (4.7 x height in inches) – (4.7 x age in years)


  • Age: Our BMR decreases as we age since the body loses 3 – 5% lean muscle mass every 10 years after the age of 30. 
  • Gender: Males have 5-10% more BMR than females, due to higher lean muscle to bone and fat ratio (higher body composition). 
  • Body weight and height: The more mass your body contains the more energy you will need. When you lose weight, your mass decreases and your BRM decreases. The opposite is also true, when you gain more mass your BMR increases. 

Maintenance calories (Total Daily Energy Expenditure or TDEE)

Your BMR is the amount of calories you need in a survival mode. However, you will need at least 20% more than your BMR to be able to perform your daily activity.

There are two types of energy expenditure here:

1- Feeding thermic effect: The amount of energy your body burns during digestion and absorption of nutrients. This accounts for more than 5% of your daily calories. 

Your body will burn more energy to digest and absorb one calorie of protein and fiber than other nutrients.

2- Activity thermic effect: This includes physical movements like job related activity and exercises. The more active you are the more energy you need to maintain your current body mass.

How the maintenance calorie calculator works

Depending on your activity level, your maintenance calorie intake is calculated as follows:

  1. For Sedentary (little or no exercise) = BMR x 1.2
  2. For lightly active (light exercise 1-3 days/week) = BMR x 1.375
  3. For moderately active (moderate exercise 3-5 days/week) = BMR x 1.55
  4. For very active ( intense exercise 6-7 days a week) = BMR x 1.725
  5. For extra active (very hard exercise and a physical job or twice a day training) = BMR x 1.9

In order to lose weight, you will need to create 500-1000 daily caloric deficit from your maintenance intake of macronutrients.

Here, you can find the weight loss calorie calculator.