What size woodchipper do I need?
Chipper sizing by property acreage, branch diameter, and tractor HP. Size to your typical branches, not your peak — and don't confuse rated capacity with comfortable working capacity.
The single biggest mistake is buying to the occasional 8-inch log instead of the everyday 4-inch branch. Size up just slightly from your 80th-percentile branch — the diameter you actually chip most of the time — not your absolute rarest maximum.
This guide gives you three ways to find the right size: by property acreage, by branch diameter, and by tractor HP. Each arrives at the same answer from a different angle. Use whichever matches how you think about your situation.
Sizing by property acreage
| Property | Chipper size | Our pick | Why |
|---|---|---|---|
| Under 1 acre | 3.5–4″ | DC-1260 | Pruning debris, minimal volume |
| 1–5 acres | 5–6″ | WC68 or B150 | Storm cleanup, mixed 3–5″ branches |
| 5–20 acres | 6–8″ | WM-8H or DCH7 | Real brush, multiple species, forked limbs |
| 20+ acres | 8″ hydraulic | MX-8800 | Hardwood volume, crooked material |
| Commercial | 9–12″ | MX-9900 or BX102S | Tree service, land clearing |
These are starting points. If your property has mature hardwoods and you regularly deal with storm damage, step up one tier. If your property is mostly open with a few ornamental trees, you may step down.
Sizing by branch diameter (the 80th-percentile rule)
Walk your property. Look at the branches that fall or need pruning in a typical year. Ignore the one big trunk from the 2019 storm. What diameter covers 80% of what you’d actually feed into a chipper? That’s your sizing target.
- 80th-percentile ≤ 2 inches → buy a 4-inch rated chipper. The 4-inch ceiling gives you margin.
- 80th-percentile 2–4 inches → buy a 5–6 inch rated chipper. The WC68 or MX-8600 hit this tier.
- 80th-percentile 4–6 inches → buy a 7–8 inch rated chipper. The WM-8H or DCH7 cover this.
- 80th-percentile 6–8 inches → buy an 8–9 inch chipper with hydraulic feed. The MX-8800 or MX-9900.
- 80th-percentile 8+ inches → commercial-grade. 10-inch PTO (Wallenstein BX102S) or 12+ inch tow-behind (Bandit, Vermeer).
Sizing by tractor HP (PTO chippers only)
If you own a tractor, your PTO HP constrains which chippers you can run. Use your tractor’s rated PTO HP(roughly 85–90% of engine HP), not engine HP. Then match to the chipper’s rated minimum.
| Tractor PTO HP | Max chipper size | Best match |
|---|---|---|
| 12–20 HP | 3.5–4.5″ | BX36S, WC46 |
| 20–30 HP | 5–6″ | MX-8500G+, WC68, BX52S |
| 30–45 HP | 6–8″ | WM-8H, MX-8600 |
| 45–65 HP | 8″ comfortable | MX-8800, BX72S |
| 65+ HP | 9–10″ | MX-9900, BX102S |
For exact numbers, use our free HP sizing calculator — it accounts for wood species and gives you minimum and comfortable HP for any branch diameter.
Rated capacity vs comfortable working capacity
Every chipper has a rated maximum branch diameter. That number is technically accurate — the machine can physically chip that size. But there’s a difference between can chip and chips well.
A chipper running at rated max on seasoned hardwood will feed slowly, bog the flywheel on knots, and wear blades faster. The comfortable working capacity— the size where feed rate stays consistent and the flywheel doesn’t slow down — is typically 1–2 inches below the rated max.
Practical rule: a 6-inch chipper works comfortably on 4–5 inch hardwood. An 8-inch chipper works comfortably on 6–7 inch hardwood. Green softwood is easier — you can push closer to rated max.
This is why we recommend sizing one tier above your typical branch: you stay in the comfortable zone instead of riding the ragged edge.
Common sizing mistakes
- Buying to the peak branch. One 8-inch trunk per year does not justify an 8-inch chipper when everything else is 4 inches. Chainsaw the exception; chip the norm.
- Confusing engine HP with PTO HP.A 35 HP tractor produces ~30 PTO HP. If a chipper needs 30 PTO HP minimum, that tractor is at the absolute floor. Size the chipper to your tractor’s PTO HP, not the number on the hood. See our HP requirements guide.
- Oversizing for “future-proofing.” An 8-inch hydraulic chipper costs $1,500–$2,500 more than a 6-inch mechanical one. If your material is consistently under 5 inches, the 6-inch does the job faster and cheaper. Save the delta for blades and maintenance.
- Ignoring feed type when sizing.A 6-inch hydraulic-feed chipper outperforms a 7-inch mechanical-feed on forked brush because the hydraulic rollers pull crooked material through. Feed type matters as much as diameter once you’re past the minimum capacity.
- Not checking 3-point hitch capacity.An 8-inch PTO chipper weighs 1,100–1,400 lb. Your tractor’s 3-point hitch has a rated lift capacity — often 1,200–1,800 lb on Category 1. If the chipper is at or near that limit, the tractor struggles to raise and transport it.
What if I'm between sizes?
If your material falls between two tiers — say, 80th-percentile is 5 inches, which could be served by a 5-inch or 6-inch — consider these tiebreakers:
- Budget tight? → size down. A 5-inch chipper at comfortable capacity is better than an 8-inch chipper you can barely afford to buy and maintain.
- Mostly hardwood? → size up. Hardwood at capacity bogs the flywheel harder than softwood. One extra inch of headroom prevents stalling.
- Forked or crooked material? → prioritize feed type over size. A 6-inch hydraulic is more productive than a 7-inch mechanical on messy brush.
- Planning to keep 10+ years?→ size up. Your property’s trees grow. What’s 4 inches now is 6 inches in a decade.
Frequently asked questions
- What size woodchipper do I need for 5 acres?
- A 5-acre property with typical brush is well-served by a 6-inch chipper. If you have mature hardwoods and storm debris, step up to 8-inch hydraulic. Our pick for 5 acres with a 30+ HP tractor: Woodmaxx WM-8H ($4,095, 8-inch hydraulic). Without a tractor: MechMaxx DCH7 ($3,499, 7-inch gas).
- What size woodchipper for a 40-acre property?
- 40 acres with active clearing needs 8-inch minimum with hydraulic feed. If you have a 40+ HP tractor, the Woodmaxx WM-8H ($4,095) is the value pick and the MX-8800 ($6,225) is the premium long-horizon choice. For 80+ HP utility tractors, the Woodmaxx MX-9900 ($7,350, 9-inch) or Wallenstein BX102S (10-inch) push into commercial territory.
- Can I size down to save money?
- Yes — as long as your 80th-percentile branch is within the chipper's comfortable working capacity (1–2 inches below rated max). The mistake is sizing down to your 50th-percentile branch — then you spend half your time chainsawing material down to fit.
- Should I size up for future-proofing?
- Only if you're likely to expand your property or take on heavier work. Trees grow — what's 4 inches now is 6 inches in a decade. But an 8-inch chipper is overkill for a suburban yard that will still be a suburban yard in 10 years.
- What's the biggest factor beyond size?
- Feed type. A 6-inch hydraulic-feed chipper can outperform a 7-inch mechanical-feed chipper on messy brush because the hydraulic rollers handle forks and crooked wood. Size matters, but feed type matters more once you're past minimum capacity.
- Is rated capacity the same as comfortable capacity?
- No. Rated capacity is the physical maximum — the machine can chip that size. Comfortable capacity is 1–2 inches lower — the size where feed rate stays consistent and the flywheel doesn't bog. A 6-inch chipper is 'comfortable' on 4–5 inch hardwood.
- How do I figure out my 80th-percentile branch?
- Walk your property after a storm or during spring cleanup. Look at the branches on the ground and the deadwood in the canopy. Measure 10 representative pieces. The 8th-largest is roughly your 80th percentile. That's your sizing target.
- What size chipper for oak and hardwood?
- Hardwood at capacity bogs most chippers harder than softwood. Size up one tier: if your branches are 4–5 inch oak, buy a 6-inch or 7-inch chipper instead of a 5-inch. The extra flywheel margin keeps feed rate consistent on dense grain.
- Do I need a different size for green vs seasoned wood?
- Green wood chips easier — you can run closer to rated max. Seasoned hardwood is the toughest load. Most sizing recommendations (ours included) assume seasoned hardwood — if you chip fresh-cut exclusively, you could size down one tier. But most owners chip a mix.
- What size chipper can I run on a 25 HP tractor?
- 25 HP engine ≈ 21 PTO HP. That's comfortable for a 5-inch chipper (Woodmaxx MX-8500G+ or Wallenstein BX52S) and at the floor for a 6-inch (Woodland Mills WC68 or Woodmaxx MX-8600). Use our HP calculator for your exact setup.