yup about 6-1/2 yds. Of course you're not doing 1" all in one shot right? I think the recommended dose is like 1/4" at a time so as not to drown your grass from sun/air. In that case, 1 yard of compost could cover 1300 sqft.

Seeing as how most of my lawn has been overtaken by Nutsedge I was going to do a large part of it with a relatively deep layer - 1/2 - 1" or so with the hope that it would give new seed a solid footing, and yes, choke out some of the existing plants. I have whole sections of yard that doesn't actually have any grass at this point.

Then on the parts that are starting to take I would lighten up a bit. 1/4" to 1/2" depending on how deep it goes into the grass - it's still pretty thin there so it should absorb it without harm.

I'm planning to seed twice - first Aug 26 and then again about the 3rd week of September. So I will divvy it up a bit.