What Size Chainsaw Do I Need? Bar Length Guide (14–36 in)

Review Information

• Reviewed by: Jack Beurge
• Review type: Research-based review
• Testing status: Not personally tested by SAWOFF — based on manufacturer documentation, reputable sources, and documented owner-reported patterns
• Published: September 22, 2026

Information in this review is labeled as one of four types: 🧪 SAWOFF hands-on test, 🏭 manufacturer specification, 📚 research from reputable sources (including documented owner-reported patterns), or 🧠 editorial assessment. See our testing methodology and editorial policy.

For most people, the honest answer to “what size chainsaw do I need” is an 18 to 20-inch bar on a 50–60cc saw. That setup covers firewood, storm cleanup, light felling and everything between. Go smaller only if your wood is small and your arms are new to the job; go bigger only if you regularly cut hardwood above 20 inches in diameter or run a mill.

The internet is full of bad rules for bar length. The worst one is “a chainsaw bar should be one third the size of the saw” — a number nobody can define, because “size of the saw” is not a unit anyone measures. The working rule that loggers and inspectors actually use is simpler:

Bar length rule of thumb: the bar needs to equal at least 2x the diameter of the wood you buck. A 10-inch oak round wants a bar long enough to reach through in one pull — about 20 inches of bar, or 18 with a careful technique and a sharpened chain. Exceptions exist for limbing and standing timber (covered below).

The rule exists because of boring cuts, not reach. When you buck a round flat on the ground, the full diameter has to be cut from one side; longer reach lets you finish the cut without pinching the bar or rolling the log. Working beyond that diameter is possible — a 24-inch bar can drop its nose and start a cut from the top through a 28-inch log — but each pass takes two cuts instead of one, and two cuts mean double the time and double the pinch risk.

Tree Diameter to Recommended Bar Size (Chart)

Match the wood to the bar first, then buy the saw class to carry that bar. This table is the short version of the “what size chainsaw do I need” question.

Tree/wood diameter	Recommended bar	Saw class	Typical cc range
Up to 6 in (branches, pruning)	10–12 in	Mini/limbing	Light battery, 25–30cc
6–10 in (small firewood)	14–16 in	Small homeowner	30–40cc
10–14 in (standard firewood)	16–18 in	Homeowner/farm	40–50cc
14–20 in (firewood, felling)	18–20 in	Farm/prosumer	50–60cc
20–28 in (hardwood, big felling)	24 in	Pro rear-handle	60–75cc
28–48 in (falling, bucking, milling)	28–36 in	Pro logger	90cc and up

Notice the arithmetic: each bar row is roughly twice the diameter row above it. That is the 2x rule doing its job, and it holds from a green alder branch to a 30-inch white oak.

10–12 Inch Bars: Limbing and Pruning

The 10–12-inch range exists for one job: getting branches off a stem that has already been felled, plus pruning standing trees you can reach from the ground. A short bar keeps the nose out of the dirt, limits kickback exposure, and stays maneuverable overhead — and since every inch of bar is weight (more on that below), a 10-inch bar makes a compact saw feel almost weightless.

This is also the home of the modern mini chainsaw, the 6–8-inch palm saws that blurred the category line. They are superb pruning tools and genuinely useful on the ground, but they are not bucking saws: their bars are shorter than the diameter of most firewood, which breaks the 2x rule before the engine even enters the conversation. A mini saw handles a 4-inch branch; it does not handle a 10-inch round.

Bottom line: buy a 10–12-inch bar for limbing a felled stem, yard pruning and clean-up, not for primary firewood work.

14 Inch Bars: The Small-Homeowner Floor

Fourteen inches is the smallest bar I would call a “real” chainsaw bar for wood you intend to split. It bucks a 6–7-inch round in one pass, drops a 10-inch yard tree without drama, and pairs with light 30–35cc engines such as the entry homeowner class covered in our chainsaw size guide.

The honest limitation is firewood volume. Cutting a winter’s wood with a 14-inch bar is physically possible but slow, because every round you prep above 7 inches takes multiple passes. If the majority of your wood comes down as 12-inch rounds, a 14-inch bar turns a half-day’s bucking into a full day.

16 Inch Bars: The Quiet Overachiever

Sixteen inches is the most underrated bar size. It bucks up to an 8-inch round in one pull, drops trees up to 15 inches in diameter without resorting to two-step cuts, and keeps the saw light enough for all-day use. Homeowners with an electric or 40–50cc gas saw get full engine performance from this length, because short bars let modest power spin the chain fast.

For anyone with a corded or battery saw, the 16-inch bar is usually the maximum that keeps cuts confident in seasoned hardwood — the point where electric and gas saws genuinely converge anyway. If your winter wood comes pre-cut to stove length, a 16-inch bar may be all you will ever need.

18 Inch Bars: The Best All-Rounder

Eighteen inches is where the comfortable majority live. It satisfies the 2x rule for 9-inch rounds, splits the difference between nimble and capable, and matches the factory configuration of the best-selling prosumer saws in the country. Both the Husqvarna 455 Rancher and the STIHL Farm Boss line ship 18-inch bars by default, and manufacturers do that for a reason: it is the bar most buyers’ wood asks for.

The 18-inch bar also carries a lower fatigue penalty than a 20-inch in hardwood, because the extra nose length on a 20 increases resistance the moment you lean on the handle. For new operators, an 18-inch is the longest bar I recommend starting with — beyond that, managing the tip becomes a skill in itself.

Bottom line: if you can’t decide between two bar lengths, buy the 18-inch and sharpen your chain more often — the decision costs you almost nothing.

20 Inch Bars: The Most Popular Chainsaw Ring Size (and the STIHL Question)

Twenty inches is the bar that firewood searches orbit around, and it deserves a section of its own because it sits at a genuine dividing line in saw classes. A 20-inch bar will buck a 10-inch round in one pull and drop an 18–20-inch tree — but the bar is only half the equation. Pushing a 20-inch bar into tight-grained oak takes engine, and this is where saw classes actually separate.

Mid-size farm saws (runs a 20-inch bar, with limits). The STIHL MS 271 Wood Boss (50.2cc, 3.49 hp) and the Husqvarna 450 Rancher (50.2cc, 3.2 hp) both accept 20-inch bars, and for rounds near 10 inches they do honest work. The 450 Rancher’s factory sweet spot is the 18-inch, with the 20 as its stated maximum — pushing green oak on the longest bar is the point where both saws tell you they would rather be at 18. Full detail lives in the Husqvarna Rancher guide and our STIHL 20-inch bar matching guide.

Pro-tier saws (20-inch bar, no strain). The STIHL MS 261 (50.2cc, 4.0 hp) pulls the same bar with noticeably more authority because its ported 2-stroke revs harder through dense wood; around firewood circles, the “stihl 20 inch chain saw” question usually ends with the MS 261 versus the heavier MS 462 (72cc-class). The 462 is the logger’s answer to a permanent 20-inch bar in hardwood — the bar spins through rounds like it is attached to a bigger saw, because it is. Husqvarna’s equivalent tier is the 460 Rancher (60.8cc, 3.68 hp, 20-inch standard, 24-inch max), the least expensive saw that treats a 20-inch bar as a permanent setup rather than a maximum.

The line between those tiers matters more than any single model. If you cut fewer than three cords a year, buy the farm saw and run a 20-inch bar in pine and poplar, accepting slower oak. If firewood is a standing commitment or the wood is mostly white oak and sugar maple, the extra cost of the pro or prosumer-upper tier buys you a longer saw life doing the same cuts. Our STIHL brand roundup lists both tiers at current street pricing, and the firewood-focused picks behind this size live in the best chainsaw for firewood guide.

Bottom line: a 20-inch bar is the national default for firewood — just make sure the saw behind it is at least a 50cc-class engine, and honestly more comfortable at 60.

24 Inch Bars: Hardwood and Serious Felling

A 24-inch bar is a real commitment. It handles 12-inch rounds in one pull and harvests trees up to 24 inches, but it also demands a 60cc-plus engine, an operator with grip endurance, and wood volume that justifies the train of setup. At this length the saw stops being a casual tool: every cut is slower to reposition, every tip is further from your eye, and the nose is more likely to snag something you did not intend.

The Husqvarna 460 Rancher (20-inch default, 24-inch max) is the cheapest respectable home for a 24-inch bar, though pro rear-handle saws in the 60–75cc class — the STIHL MS 462 or Husqvarna 572 XP — carry it the way it was designed. Felling technique is a bigger part of the job here: brush up on felling before speculating on big timber, because a 24-inch bar in green hardwood is the point where technique failures stop being embarrassing and start being injuries.

28–36 Inch Bars: Logging and Mill Work

Bars in the 28–36-inch range are professional tools, and buying one without the saw to run it is a common backyard mistake. These lengths exist for two jobs: felling mature timber (30-inch-plus trees need the bar to match the hinge wood) and bucking large diameter rounds or slabs for mills. The engines behind them are 90cc-class monsters such as the STIHL MS 661 and Husqvarna 395XP, with weights to match, and the guide bars themselves are different hardware — often lightweight or structural-core bars rather than the consumer laminate style.

Mill work has its own bar family: ripping chains and dedicated mill bars for chainsaw mills, covered in our milling saw roundup. Ripping cuts run the length of a log rather than across it, which loads the engine completely differently, and that is also where chain choice re-enters the picture — our full-chisel vs semi-chisel breakdown explains the trade-off in detail.

Bottom line: a 28-inch-plus bar is a logger’s or miller’s tool. Buy it after the saw class, never before.

How Bar Length Raises Kickback Risk

Bar length and kickback force are directly linked, and it is the second reason (after weight) that bigger is not safer. Kickback happens when the upper quadrant of the bar nose strikes wood — and a longer bar has a longer nose arc, meaning more of that quadrant is exposed with every cut geometry you use.

Three factors scale up together as the bar grows:

Bar length	Nose arc exposure	Typical kickback risk class
10–16 in	Limited	Low (consumer rated)
18–20 in	Moderate	Moderate — technique matters
24 in	Significant	Reduced-margin — pro techniques expected
28–36 in	Large	High — felling-specific design required

The practical takeaway: the longer your bar, the more rigidly you need to honor the rule of never letting the upper nose touch anything. Wrap your thumb, stand to the side of the cut line, and let the chain brake do its inertia job. Shorter bars also hold a low-speed advantage on battery saws, because control matters more than reach.

Weight: What Each Extra Inch Costs

Bar length is not free weight, and the cost is not linear at the nose — it is calculated and you carry it all day. As a working figure, every extra 2 inches of bar with chain adds roughly 0.6–0.8 pound, and the majority of that is chain and oil rather than the bar rail. The summary for planning:

• A 14-inch setup on a mid-size saw typically runs about 2 pounds lighter than a 20 on the same powerhead.
• A 20-inch setup turns a 10.8 lb pro saw into roughly a 13 lb working tool.
• A 28-inch bar on a pro saw adds 3–4 pounds over the 20-inch configuration, on top of a 14 lb-plus powerhead.

Weight matters because fatigue, not ignorance, causes most chainsaw accidents. The last 30 minutes of a cutting session with an overloaded bar is statistically the most dangerous window of the day, so if your wood can be handled with an 18-inch bar, there is no virtue in the 24.

What Size Chainsaw Should You Buy?

Sorting the whole guide down to answers by user type:

• Limbing, pruning, small yard cleanup: a 10–12-inch bar, often as a compact mini or top-handle saw. Buy it alongside, not instead of, your main saw.
• Homeowner, small firewood, yard trees under 14 inches: a 16-inch bar on a 40–50cc saw, or the top-tier battery equivalents. See the best chainsaws of 2026 for current picks.
• Firewood and farm use, the question behind most “what size chainsaw do I need” searches: an 18–20-inch bar on a 50–60cc prosumer or pro saw — the Husqvarna 450 or 460 Rancher, STIHL MS 271, or MS 261 depending on volume.
• Hardwood above 20 inches, serious felling: 24-inch bar behind a 60cc-plus pro saw.
• Big timber and milling: 28–36-inch bar behind a 90cc-class logging saw — see the logging saw roundup.

The 2x rule is the whole game. Measure your wood, double the number, buy the bar that matches — and add an 18-inch margin note in your head for the day your cousin shows up with a 26-inch oak that needed half a day and a rented pro saw.

Frequently Asked Questions

What size chainsaw do I need for firewood?

For firewood, a 16 to 20-inch bar covers nearly everything split at home, since a bar should be at least twice the diameter of the rounds you buck. An 18 or 20-inch bar on a 50–60cc saw such as the Husqvarna 450 Rancher or STIHL MS 271 is the sweet spot.

What size chainsaw do I need to fell a tree?

The bar only needs to match the tree's diameter plus a little overhead for the felling hinge, but power matters more than reach on standing timber. For trees under 14 inches, a 40–50cc saw with an 18-inch bar is enough; for hardwood above 20 inches, step up to a 60cc-class saw on a 20 to 24-inch bar.

Is a longer chainsaw bar safer or more dangerous?

Longer bars are more dangerous. Kickback force rises with bar length because more nose area and more chain speed can strike an object at once, and a heavier nose is harder to control through long cuts. Match the bar to the wood and no larger.

Will a longer bar fit my chainsaw?

Check the manufacturer's maximum recommended bar length for your model — going beyond it starves the chain of engine power and stresses the clutch and oiler. An 18-inch saw can often run a 20-inch bar, but a 50cc saw should not push a 24-inch bar into hardwood.

How does bar length affect chainsaw weight?

Every extra 2 inches of usable bar and chain adds roughly 0.6 to 0.8 pound, with the chain itself the heaviest part. A 20-inch setup on a pro saw typically runs 3 to 4 pounds heavier than the same powerhead with a 14-inch bar.

What is the most popular chainsaw bar size?

The 20-inch bar is the most popular size for firewood and farm use in the US, and it matches both the Midwestern white-oak rounds and the typical 50–60cc Farm Boss class of saw. An 18-inch bar remains the best compromise for most homeowners, since it weighs less and is easier to control.