Formula for calculating calories burned during exercise

[jg42058p]

Is there a formula out there that can be used to calculate (estimate)
How many calories one has burned during an exercise session of a given time and intensity?

I imagine this would be based on age, weight, body fat%, height, gender, time, and workout intensity

For example, I saw on a website (http://www.nutritiondata.com/tools/calories-burned) that gave such an estimation.

I said I was 24yrs old, 6ft, 245lbs, had a very active life style and ran for 45minutes at 5.2mph

Using some formula (I’m trying to figure out what that formula is) it said I burned around 856kCal from jogging.

Any ideas on what the mathematical formula is?
Are there any better formulas out there?

I would like to know the specific mathematical formula, so I can plug it into my excel spread sheet to monitor my progress.

Thanks guys.

[eatrainrest]

geta good HR monitor watch if your really concerned but you could ideally estimnate based on your RECOVERY HR and BPM.

[viciouspoultry]

It completely depends on the heart rate, website like those give a general idea but are not fully accurate I agree with eatrainrest on the HR if you are concerned

[FireGuy]

You would have to know you LBM down to the pound to accurately calculate anything.

[Deltasaurus]

website over calcs bigtime unless ur and ecto