Yeah, I do. I have an excel spread sheet that I have come up with over the years. I plug in the sq ft of the yard and it will calculate where my price should be. Don't really use it for residential stuff much because most of our res stuff is 4-10K sqft and that's relatively simple.
You have to be careful using a one size fits all calculator. 50K sq ft of open turf with new plantings is totally different than the same size property 10 years old and cut up into little areas of turf.