This was great. I'm not sure if it is the one at the top of the daily thread. Look at page 4:
Basically, if Phase 1 is about 750, Phase 2 is about 1100, so Phase 3 is about 1400 to 1500.
With Phase 3, you are adding up to 65g total carbs from grains, fruit & dairy and 15g from fat. So whatever your P2 totals for carbs, protein and fat, they will now be higher by 65g (about 115g or more total) for carbs, maybe 5g or so more for protein (about 115g) and another 15g higher for fat (about 53g).
Try this: Go into the "custom" setting of MFP, set the calories at 1400. Set the Carbs to 35%, the protein to 35% and the fat should follow to 30%. That's about as close as MFP lets you account for things. Don't worry about the fiber. Subtract fiber from carbs to get net carbs is that is what you are after.
None of this is necessary, of course, because of the way that IP is designed.
What IS VERY NECESSARY is to pay careful attention to what you are doing for that Phase 3 breakfast as THAT is what needs to match up to 30g from grains, up to 20g from fruit and up to 15g from dairy for the carbs and up to 15g for the Fat, with a 25g minimum for protein. And all that needs to be between 400 and 500 (not less and not more).
Lots of p3 breakfast idea threads for the foods and calcs that others have done.
Kind of a long answer to a short question. Hope that is some of what you were after.