How Many Calories Do I Burn a Day? (w/ Online Calculator)

Updated in November 2022

The body requires a minimum amount of energy to ensure normal bodily functions (like maintaining a heart rate and breathing) and to perform activities of daily living, like working, exercising and cleaning. This energy is usually measured in calories. 

To calculate the amount of calories you burn in a day, you can use the formula provided by the World Health Organization. This formula calculates the energy used for bodily functions while taking gender, current weight, age and activity level into consideration. 

You can use the following calculator to calculate how many calories the body needs per day by entering your data below: 


How to calculate daily burned calories 

Your daily calories can be calculated using the WHO formula that looks at energy needed for maintaining normal functions and your activity factor. Your activity factor is the average activity level you employ on a daily basis to perform activities of daily living, like evercising, working or cleaning. 

How to calculate the calories the body burns 

The formula used to calculate the amount of calories the body uses to perform normal bodily functions will vary with gender, current weight and age: 




0 to 3 years old

(58.317 x weight in kg) – 31.1

(59.512 x weight in kg) – 30.4

3 to 10 years old

(20.315 x weight in kg) + 485.9

(22.706 x weight in kg) + 504.3

10 to 18 years old

(13.384 x weight in kg) + 692.6

(17.686 x weight in kg) + 658.2

18 to 30 years old

(14.818 x weight in kg) + 486.6

(15.057 x weight in kg) + 692.2

30 to 60 years old

(8.126 x weight in kg) + 845.6

(11.472 x weight in kg) + 873.1

≥ 60 years old

(9.082 x weight i. kg) + 658.5

(11.711 x weight in kg) + 587.7

What is the activity factor?

The activity factor considers the type of activity and average time it takes to perform it: 

  • Mild - Average activity factor of 1.55: Mild activities include cooking, cleaning the house, taking care of the children, working in a seated position and walking about an hour per 
  • Moderate - Average activity factor of 1.84: Moderate activities include an hour of running, cycling, swimming or dancing; working in construction or as a waiter, door-to-door vendor, or delivering.
  • Intense - Average activity factor of 2.2: Intense activities include swimming, walking, biking or dancing over 2 hours per day, working in a farm, working in manual labor, walking long distances many times per day, or delivery heavy packages 

Example of formula of daily calorie expenditure

A woman who is 32 years old and weight 70 kg wants to calculate how many calories she burns to day. She works in a seated position every day and walks 5 times per week. The formula can be used in the following way: 

Basal calorie expenditure: (8.126 x 70 kg) + 845.6 =  1414,42 calories.

Total calories burned:  1414.42  calories  x  activity factor (1.55) 

The total number of calories this woman burns per day is 2102.35. 

Difference between basal calorie expenditure and total calories burned 

Your basal calorie expenditure is the amount of energy your body needs just to maintain normal functions, like breathing, heart beats and brain activity. 

Total calories burned also includes the calories needed to complete activities of daily living. 

Why total calories burned may vary 

There are many factors that can influence how many calories your body burns per day, like your current weight. People who weigh more will require more calories to complete the same activity that a person who weighs less needs. 

Another factor to consider is the type and amount dedicated to activities of daily living. A person who works in a sedentary job and does not exercise will require less energy than a person who also works in a sedentary job but exercises 5 hours per week. 

Certain health-related conditions, like pregnancy, surgery, or malnutrition can boost metabolism rates, which increases your daily caloric needs. 

Why it’s important to know how much you burn 

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Knowing how many calories you burn per day is important for those who are concerned with their weight. It is a tool that can be used to understand how much food should be eaten every day to achieve certain health goals, like gaining or losing weight.

If you are looking to lose weight, you should ideally consume less calories than you burn. To maintain your weight, you should consume the same amount of calories you already burn. To gain weight, you should consume more calories than you burn. Read more about how many calories you should eat per day.