Formula for converting Grams of P/C/F to a caloric percentage

[QUOTE][i]Originally posted by wake_me_420 [/i]
[B]I'm still trying to understand how to work a split such as a 40/40/20. These numbers represent a percentage of calories taken in correct? If I know my daily totals in grams of p/c/f is there a mathematical formula to convert grams of these sources in to calories?

thanks [/B][/QUOTE]

Yes - the numbers represent the percentage of your daily calories...

So, say you were eating 2500 cals, that would mean:

40% of cals would be from carbs.
40% of 2500 = 2500 x 0.4 = 1000 calories.
As carbohydrates are 4 calories per gram that would = 1000/4 = 250g carbs.

40% of cals would be from protein.
which is 1000 cals again.
Protein also has 4 cals per gram which would be 250g protein.

20% of cals would be from fat.
20% of 2500 = 2500 x 0.2 = 500 cals.
Fat has 9 cals per gram, so 500/9 = 56g fat