Calculating percentages of fat/carbs/protein

Can someone direct me to a tool that will help me calculate the number of grams of fat/carbs/protein I need to eat to maintain a 25% / 35% / 40% diet? I'm currently eating 1300 calories a day plus exercise calories, but I want to start paying attention to the ratios. Fresh start!

if you set your macros to that here ( custom goals ) then you can see the grams at the bottom of the columns of the food diary (and when you use the settings thing)

http://www.myfitnesspal.com/account/change_goals_custom

Or did I misunderstand ?

That's an easy one:

1 g of Fat = 9 calories/gr
1 g of Protein = 4 calories/gr
1 g of Carb = 4 calories/gr

If you are eating a ration of 25/35/40 at 1300 calories/day

0.25x1300 = 325 cal fat / (9 cal/gr) = 36g Fat
0.35x1300 = 455 cal carb /(4cal/gr) = 113.75 - round up to 114 g carbs
0.40x1300 = 520 cal protein/(4cal/gr) = 130 g protein.

You can also change the ratios on your goal area in MFP. I don't go with what they recommend, personally - the numbers are too low and its waaaay too carb heavy. I'm currently eating at 40/20/40 (fat/carbs/protein) and doing great.

Professional hazard : )

I work in IT.