A calculator to estimate how many calories you burn in a day
About 70% of a human's total energy expenditure is due to the basal life processes taking place in the organs of the body. About 20% of one's energy expenditure comes from physical activity and another 10% from digestion of food. BMR (or Basal Metabolic Rate) accounts for about 60 to 75% of the daily calorie expenditure.
A common weight loss tactic known as CICO (Calories In - Calories Out) is to eat fewer calories than what you burn in a day to eventually lose weight. This approach may be too simplistic, however it does help curb overeating and maintain portion control.
The idea is to create a calorie deficit to lose weight over time. The calorie deficit is the difference of the calories you consume and the calories you burn throughout the day. 1 lb of fat corresponds to about 3500 calories. Therefore, to lose 1 lb of fat over a week you would need to maintain an average calorie deficit of 500 calories throughout the week.
Several equations have been published from the the early 20th-21st centuries to predict the number of calories required by humans, however these can merely provide a rough estimation.
Assuming
The Harris-Benedict Equation was one of the earliest equations introduced. It was revised in 1984 to be more accurate.
The Mifflin-St Jeor Equation was introduced in 1990 and was show to be more accurate than the Revised Harris-Benedict Equation.
The Katch-McArdle Formula takes lean body mass into account which can be more accurate for people who are leaner and know their body fat percentage.
This project comes with batteries included out of the box! Simply clone the repository to get started.
Open the index.html file in your preferred web browser.
Make sure that javascript is enabled.
You can see a live demo of the app here.