Calories burned estimate?

[BigFate]

I'm curious to know how websites like fitday.com calculate how many calories burned?

For example I just entered my daily macros and it was 1,809 cals and 3,131 burned? How does it accumlulate that? And how the hell am i burning that many cals?

[BigFate]

Reps to whoever can break this down to me for a sec...

[foodandfitness]

These equations are simply estimates. They are derived from formulas. A common formula we use to assess caloric need is the Harris Benedict equation:

Women: BMR = 655 + ( 4.35 x weight in pounds ) + ( 4.7 x height in inches ) - ( 4.7 x age in years )
Men: BMR = 66 + ( 6.23 x weight in pounds ) + ( 12.7 x height in inches ) - ( 6.8 x age in year )

And then multiply that by an activity factor:

To determine your total daily calorie needs, multiply your BMR by the appropriate activity factor, as follows:

If you are sedentary (little or no exercise) : Calorie-Calculation = BMR x 1.2
If you are lightly active (light exercise/sports 1-3 days/week) : Calorie-Calculation = BMR x 1.375
If you are moderatetely active (moderate exercise/sports 3-5 days/week) : Calorie-Calculation = BMR x 1.55
If you are very active (hard exercise/sports 6-7 days a week) : Calorie-Calculation = BMR x 1.725
If you are extra active (very hard exercise/sports & physical job or 2x training) : Calorie-Calculation = BMR x 1.9

So long story short, the website uses a formula such as the one above, to figure this out. They can take your height, weight, age, and come up with a basal metabolic rate. This is then multiplied by an activity factor to come up with an estimate.

These are just estimates. Equations. They are not perfect, but more or less accurate enough to serve most needs. You can get a test done through indirect calorimetry to find out more specifically for you, but you would need to go to a sports clinic or university to find something like this. Hope that helps!

[BigFate]

Repped ! Thanks for breaking that down for me..