Converting recipes- extract to PM/AG to PM

So I've been browsing the recipe database, having made the decision to do PM on the path to AG brewing. Is there a conversion factor for converting extract to PM, or AG to PM?

I'm a Macophile, so I'm tinkering with Beer Alchemy.

1 lb of base grain = .8 lb liquid extract = .6 lb dry extract.

I use Palmer's countertop PM method from BYO using 4 lbs of grain in a 2 gallon cooler. I mash all of my specialty malts with as much base malt as I can squeeze in to get to 4 lbs. I then figure out how much extract the base grains are worth, and subtract that from the total extract amount in the recipe.

Using BeerAlchemy, set your procedure to the partial mash setting for an acurate assesment of your recipe.

Cheers!

There's a ton of good threads with plenty of info/tips already on here, including links to some great articles and pdf files for doing it. Use the search function and you will find all the info you need.

Thanks for the advice, all. I located the Ken Schwartz article via the search and will spend some time poring over it later today.