Best 20-Inch Chainsaw 2026: Enough Bar for Felling, Storm Cleanup and Firewood

A 20-inch bar is the called length, measured over the whole bar. About two inches of it sit inside the powerhead, so the usable cutting length is roughly 18 inches. That makes 18 inches the realistic maximum trunk diameter for a single-pass cut, with the bar buried to the tip on one side.

Cutting from both sides of the trunk to meet in the middle roughly doubles the practical diameter, into the low-to-mid 30s of inches. Treat that as an experienced-operator method, not a shopping target: on the second cut the tip works blind inside the wood, and if the two cuts do not line up the bar gets pinched.

The working rule of thumb is bar length equals log diameter plus about two inches. A 20-inch bar is the right tool for 16 to 18 inch wood and the wrong tool for a 24-inch trunk. Bucking a log on the ground is easier than felling a standing tree of the same diameter, because the ground supports the log and you can finish the cut from one side with a little roll.

For a gas saw, 50 to 60 cc is the sweet spot for a 20-inch bar, with about 50 cc as the floor for a consumer model. Each additional two inches of bar wants roughly 5 to 10 cc more displacement. For battery, the equivalent is a saw advertised at 50 cc gas equivalence or better, which is now common on 20-inch cordless models.

An underpowered saw on a long bar tells you so. The engine bogs in the cut, the chain stalls when the bar is buried, the powerhead runs hot, and the clutch slips or glazes. The cut also wanders, because the operator leans on the saw to keep it moving instead of letting the chain do the work.

Displacement alone does not tell the whole story: professional-grade 45 to 50 cc saws pull a 20-inch bar because of torque and lighter construction. But a homeowner saw at 40 cc on a 20-inch bar is a mismatch. Past 20 inches the powerheads get heavy and expensive, and the saws are built for professional logging rather than property work, which is why the homeowner class tops out here.

"20-inch chain" is not a specification. A 20-inch bar takes a chain defined by its pitch, its gauge and its drive-link count. The common combinations on 20-inch bars are .325-inch pitch with .050-inch gauge and 78 to 80 drive links on 50 cc-class saws, 3/8-inch pitch with .050-inch gauge and 72 drive links on 55 cc-and-up saws, 3/8-inch low-profile on some lighter models, and .325-inch with .058 or .063 gauge on certain pro saws.

Pitch is the distance between drive links, which sets how the chain rides the sprocket. Gauge is the thickness of the drive-link tang, which sets how it fits the bar groove. A chain of the right length but the wrong gauge will not seat properly, and two chains of the same pitch and drive-link count but different gauge look identical on the shelf.

The authority is the stamp etched on the bar tail. That stamp, not the bar length, is what you match when buying a replacement. A loose-fitting chain can derail, and a too-tight one binds and overheats the bar, so the wrong chain costs you both cut speed and safety.

The extra reach pays when you fell medium trees in the 14 to 18 inch range, buck firewood where the log is too big to roll comfortably, or clear storm damage where the limb is down and you want to reach across it without repositioning your feet.

A shorter bar is faster and safer for limbing and pruning, for cutting small branches overhead or at awkward angles, for tight quarters, and for any task where you hold the saw up rather than down. The physics is simple: a longer bar means more chain to keep sharp, more weight out front and more tip in play, so it is slower in small wood and more tiring over a long session.

A 20-inch saw suits a property of an acre or more with regular firewood and felling work. A 16- or 18-inch saw suits most suburban yards and occasional limbing. Many 50 cc powerheads ship with an 18-inch bar and accept a 20-inch bar within the manufacturer's approved range, so buying the shorter kit and adding a longer bar later is a legitimate route, provided the manual lists that length as approved.

The extra length shifts the saw's center of gravity forward, away from the rear handle, so your wrists and forearms carry more of the weight and the saw feels heavier than its bare weight suggests. The kickback zone is the upper quadrant of the bar nose, and a longer bar puts more nose further from your hands, so the same rotational force has more leverage.

Consumer saws are required to ship with a low-kickback chain, which reduces but does not eliminate kickback. The inertia chain brake, chain catcher and right-hand guard are the backstops. Technique is what keeps a 20-inch bar controllable:

• Keep the saw at full throttle through the cut rather than feathering it.
• Avoid boring or plunge-cutting unless you have been trained.
• Keep the nose clear of the wood when you finish a cut.
• Stand to the side of the cut line rather than behind it.
• Never cut above shoulder height with a rear-handle saw.

Fatigue is the quiet risk. Most chainsaw injuries happen late in a session, when the arms are tired and the saw is being muscled rather than guided. The right 20-inch saw is the one you can run for hours, not the one you can lift once.

A 20-inch bar plus powerhead needs a scabbard or case sized for the full length. A case built for an 18-inch saw will not close over a 20-inch bar, and an ill-fitting scabbard lets the chain teeth catch on the vehicle or your leg. In a truck bed the saw lies across the bed; in a sedan trunk it goes in diagonally, so measure before assuming it fits.

On an ATV or UTV, mount a scabbard to the rack and point the bar away from the rider. For storage, hang the saw by the rear handle or set it on a shelf with the bar supported along its length rather than resting on its tip, which over time can bow a long bar. A 20-inch bar bends more easily than a short one because of the leverage, so never lean it against a wall by the nose or use it as a handle.

For a gas saw going into long storage, drain the tank and run the carburetor dry, and keep bar oil in its own container.