What does stump diameter mean?
Stump diameter is the width straight across the stump, in inches. Think of a line that crosses the stump through its middle. That line is the diameter.
Iowa State University Extension gives the pricing rule: “Arborists will charge by the size of the stump, measuring it at its widest point.” Angi’s 2026 national cost guide says grinding “is priced by diameter inch.” Together the two sources say the same thing. The stump diameter is the number most price quotes start from.
Where on the stump do pros measure?
Practice varies, so ask. Iowa State says “widest point,” but it does not say at what height. A tree service blog for operators, DoorstepHQ, is more specific: “Measure at the widest point of the root flare at ground level, not at the trunk cut.”
The same blog explains why. When a tree is felled, the cut is made above the root flare, sometimes 12 to 18 inches above it. Its example reads 14 inches at the cut and 22 to 24 inches at the flare. The root flare is the widening at the base where the trunk meets the roots. The grinder has to work through that wider base.
| Where you measure | What you get | Watch for |
|---|---|---|
| Cut face | The width of the trunk where it was cut | Often narrower than the base |
| Ground level, at the flare | The width the grinder works through | Includes surface roots that flare out |
Two quotes on the same stump can differ if they measure in different spots. Ask each company where it measured.
How do I measure an oval or uneven stump?
Many stumps are not round. Measure the longest line and the shortest line, and send both numbers. DoorstepHQ gives one method for oval stumps: add the long and short measurements and divide by two. Iowa State says to use the widest point. Neither is a rule every company follows.
If you can only wrap a tape around the stump, you have the circumference, not the diameter. Divide the circumference by 3.14 to get the diameter. A 63-inch wrap gives about 20 inches across. Tell the company which number you are giving.
How does diameter turn into a price?
A company multiplies the diameter by a per-inch rate, then checks the result against its minimum charge. Angi’s guide says most jobs run $2 to $5 per diameter inch, and that nearly all contractors apply a minimum fee. Those are national guide figures, not a price for Cincinnati Stump Grinding, which publishes no price list. See the cost per inch guide and the minimum charge guide.
Height and wood type can also change a quote, but the diameter does most of the work. See how to measure a stump for a quote for the full set of steps.
How do I send my measurement?
Give the width in inches and say where you measured. Then add two or three photos with a tape measure next to the stump. Cincinnati Stump Grinding grinds stumps in Dayton, Cincinnati and Northern Kentucky and says it can usually give a free quote very quickly without an in-person visit. The photo quote post lists what to send. For the whole cost picture, read stump grinding cost.
What size groups do cost guides use?
Some guides sort stumps into small, medium and large. LawnStarter’s cost guide, modified October 5, 2026, lists small as up to 10 inches, medium as 10 to 30 inches, and large as over 30 inches. Its prices for each group are national averages. They are not quotes.
Other guides give a price by exact size instead. Angi lists average costs for 6, 12, 18 and 24 inch stumps. The two guides group stumps differently, so a “medium” stump in one guide is not the same as in another. Always use your own measurement, in inches.
The table shows how a wrap-around tape reading converts to a width, using the 3.14 rule above.
| Tape around the stump | Width across, about |
|---|---|
| 31 inches | 10 inches |
| 63 inches | 20 inches |
| 94 inches | 30 inches |
If your stump is not round, the wrap method is less exact. Measure across it instead.
Why does the measuring spot matter to the price?
Because the price scales with the number. Angi’s guide reports that most jobs run $2 to $5 per diameter inch. At any rate, a 14 inch reading and a 22 inch reading on the same stump produce very different totals. The DoorstepHQ example above shows how that happens when one quote measures the cut and another measures the flare.
This is why two honest quotes can differ. The gap may come from the measuring spot, not the rate. Ask each company to state the width it used, then compare the quotes on the same number.
Next step
Measure your stump across the widest point and note where you measured. Call (513) 587-6772 or send photos for a free estimate.
Frequently asked questions
What is stump diameter?
It is the distance straight across the stump through its center, in inches. Iowa State Extension says arborists charge by the size of the stump, measuring it at its widest point. Pricing by the inch uses this number.
Do I measure around the stump or across it?
Across it. Diameter is a straight line through the center. If you wrap a tape around the stump, you get the circumference. Divide by 3.14 to get the diameter. Send the across measurement to a company, and say how you got it.
Why do two quotes use different widths for the same stump?
Companies may measure at different spots. A trade blog for operators says to measure the root flare at ground level, not at the cut, because the cut face is almost always narrower. Ask where each quote measures before you compare prices.
Terms on this page
Sources
- Iowa State University Extension: How to Remove Tree Stumps
- DoorstepHQ: How to Estimate Stump Grinding Jobs Accurately
- Angi: How Much Does Stump Grinding Cost? [2026 Data]
- LawnStarter: Pricing Guide, How Much Does Stump Grinding Cost?
Written by Cincinnati Stump Grinding and checked against the sources above on October 26, 2026. City rules and product guidance change, so check the linked page before you act.