Cost
Per-inch pricing
Per-inch pricing sets the price of grinding a stump by its diameter in inches, measured across the widest point, so larger stumps cost more.
Per-inch pricing multiplies a rate by the stump's diameter. Iowa State Extension says arborists charge by the size of the stump, measuring it at its widest point. A 30-inch stump costs more than a 10-inch stump at the same rate.
Companies set their own rates, and many add a minimum charge so small stumps still cover the cost of bringing the machine. Some also count height above ground, extra roots or several stumps on one visit. Reported prices vary by area and year, so ask each company how it counts.
To get a fair quote, measure the stump diameter the same way the company does. See stump grinding cost per inch and how stump diameter is measured.