Stump grinding cost in Washington and Oregon

Modeled per-inch pricing

Stump grinding is sold by the inch because the grinder’s time rises with the width of wood it has to chew through. The model uses $4–$6 per inch of stump diameter at the ground, with a $150 minimum per visit for the trip and the machine, every figure rounded to $50. The rate is the same in both states: a stump visit is usually one operator and one machine, so the state wage gap behind the crew-hour rates on the tree removal cost page does not drive it [7].

Modeled estimate, not quotes (method). One row worked: 30 in × $4–$6 is $120–$180; the $150 floor lifts the low end, and $180 rounds to $200.

The operator’s time is still mostly wages. BLS’s May 2025 mean hourly wage for tree trimmers and pruners is $35.04 in the Portland metro and $33.85 in the Seattle metro, against $26.91 nationally, a labor index of about 1.30 and 1.26; Spokane, at $25.94, sits slightly below the national mean [7]. That is a wage comparison, not a price, but it is one reason per-inch rates quoted in national articles may not match what Portland and Seattle operators charge.

Grinding leaves the roots in the ground. Digging out the whole root plate is a different job with an excavator, covered on stump removal versus grinding. Added to a removal, grinding is the $150–$450 line in the tree removal cost calculator.

How diameter is measured for pricing

The model measures across the widest part of the stump at ground level, flare included, because that is the width the cutter wheel has to cross. A permit code measures a living tree somewhere else: Portland regulates private trees at 12 in DBH, taken 4.5 ft above the ground [8]; Redmond’s significant-tree threshold is 6 in DBH at 4.5 ft [9]; Bellevue measures its 6 in threshold at 4 ft [10]. A Douglas fir or bigleaf maple is much wider at the ground than at chest height, so the number on your permit is smaller than the number on your stump bid.

• Who measures, and where. Have the bidder tape the stump in front of you, at the ground, at its widest, and write the inches on the quote.
• Tall stumps. A storm-snapped trunk or a knee-high stump has to be cut to the ground first, and that saw time is a separate line.
• Clumps. A multi-stem vine maple or arborvitae grown together is measured across the whole mass as one stump.

How far apart stump bids can be

Diameter bands are how public agencies buy stump work, and their bid sheets show how widely operators price the same item. The City of Tulsa, Oklahoma’s 2024 emergency debris contract (TAC 1326) asked nine bidders for a per-stump price, on an as-directed basis, in three bands [18]:

These are Oklahoma municipal bulk-contract bids from October 2024, not Washington or Oregon prices, and they are not inputs to the model above. What carries over is the spread: the highest bid was roughly five to ten times the lowest for the same stump band. Get at least two written quotes with the diameter, depth and grindings plan spelled out, so you are comparing the same job.

Depth add-ons and root chasing

The per-inch rate buys a standard grind: the stump and the top of the root flare taken far enough below grade to rake soil over and seed. Two things go past that, show up as separate lines, and are not priced by the model.

Deeper grinds. Replanting in the same hole, setting a fence post, or pouring a patio over the spot all need the wood gone deeper. More passes, billed as time. Say what the spot is for and get the depth in inches on the quote.

Root chasing. Surface roots running across the lawn from a bigleaf maple, a cottonwood or a fir can be ground along their length, billed by the foot or the hour. Worth it where they lift a walk; a waste where they will rot under the grass. Where laminated root rot killed the tree, the Oregon Department of Forestry recommends removing infected trees and susceptible hosts in a 50–75 ft buffer, then either stump removal or replanting with resistant species [11]; see laminated root rot.

Call 811 before anyone grinds: it is free, and the law requires it

A grinder wheel can reach a buried gas service or power feed, so the locate comes first. In both states it costs nothing, and the homeowner exemption covers only digging shallower than 12 inches, which a stump grind is not.

The person running the machine should hold the ticket; ask for the number before the grinder is unloaded. 811 marks utility-owned lines; lines you own past the meter, like irrigation or the feed to a shop, are yours to point out.

Access, number of stumps and hauling the grindings

Access. A tow-behind grinder needs a gate it fits through. Where it cannot get in, the operator brings a slower walk-behind machine or pulls a fence panel. A stump on a slope, behind a retaining wall or against a foundation takes more time, and the quote should say so.

Number of stumps. The $150 minimum is a per-visit floor in the model, not a per-stump charge. Ten 6-inch arborvitae stumps add up to 60 inches, which models at $250–$350 for the batch; one at a time they would be ten minimums. Bid every stump in one visit, and ask whether the operator prices by total inches or per stump.

The grindings. A 36-inch stump leaves a mound of chips and soil larger than the stump was. Cheapest is leaving it in the hole to settle; next is raking it into beds as mulch; dearest is hauling it and backfilling with topsoil, a separate line with a dump fee. Two Oregon pests change the answer. In Oregon’s Washington, Yamhill, Marion, Clackamas and Multnomah counties, ash stumps, roots, chips and mulch are regulated under the emerald ash borer quarantine, OAR 603-052-1075, and may not leave it without an ODA compliance agreement; ODF says ash material may move as chips 1 inch or smaller [12][13]. For Oregon white oak with Mediterranean oak borer, ODF says to chip the infested tree, stump included, on site to 1 inch or smaller and not to move oak firewood more than 10 miles [14]. Ask what the crew does with ash or oak grindings; emerald ash borer in Oregon has the county map.

What a stump grinding quote should list

1. Each stump’s diameter in inches at the ground, and the per-inch rate or flat figure.
2. Grind depth in inches, and whether roots will be chased, by the foot or by the hour.
3. Cutting any tall stump to grade, as its own line.
4. What happens to the grindings: left, raked, or hauled with backfill.
5. The 811 ticket number, or who will call it in.
6. Access notes: gate width, fence panel, slope, protection for the lawn and walk.
7. Guarding. OSHA’s 2021 tree care inspection memo tells inspectors to check machine guarding on stump cutters and cites the line-clearance rule that stump cutters be equipped with enclosures or guards to protect employees (29 CFR 1910.269(r)(4)(i)) [19]. A machine with its guard or chip curtain in place also keeps chips off your windows and car.
8. A license number. Oregon says in plain words that stump removal needs an LCB or CCB license [15], and ORS 701.005 lists removing stumps in its definition of contractor [16]; Washington’s contractor definition names tree removal services [17]. Check it at the Oregon license lookup or the Washington license lookup.

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