Pricing at one flat rate per inch is not that accurate in determing your work load. I look at the job and figure how long it is going to take me. I know it cost 70/hr just to run the machine if you include replacing, carbide, belts, pulleys, bearings, oil changes, pockets, bolts, fuel ect. remember you are depreciating the machine over a set amount of time 5 years 6,7, maybe even 10 depending on how many hours you are grinding a year. You really have to look at everything it cost to grind stumps in the first place including how much it cost you everyday just to wake up in the morning , 75 bucks to roll out of bed? Insuranes and everything all combined.
You have to look at the job by time and complexibility. Rock hazards, are the stumps cut low, are you going to flush cut them low? Are you going to smoke a chain, hit a nail? How does the wood grind. Is it going to take a while. Is it dense and heavy wood like beech? is it brittle and smooth to grind like oaks? Is it fresh and wet or rotten? Is it a hard and dry from sitting all summer durning a drought? Are the roots from a red maple running several feet away from the trunk? What are the clients planning to do with the area? do you have to break through the core so you can have proper flow of water for planting? can you just take it down an inch to hide for a mulch bed?
After you answer all these questions and more, start to think about volume. The radius of a circle squared times pi gives you it's area. Think of the difference of the volume of wood you are going to have to chip between a 1 foot stump versus a 5 foot stump. 113 face cu. inches versus 2826 face cu. inches. You can see the volume increases exponentially the larger you go. So if you charge 2 dollars an inch for a 1 foot stump or 24 dollars, don't charge 120 dollars for the 5 foot stump with 25 times as much cu face. The larger stump is the more work, and when you get used grind time you will understand this.
when pricing - Know you wood and look at all the factors and remember don't undercut yourself. These are imaginary stumps in my example but charge 600.00 or more for the five footer
... remember the chips build up and things get a lot more complicated with bigger stumps 10 dollars and inch is not really that off when you think how much the volume increases. You will get to the point when you can just look and tell. You will know all the factors that determine your price including what others are charging and your exact costs. Hope this helps. Good luck... Justin 860-874-1205 STUMPS IN CT...