How to Choose a Chainsaw | Bar Length, Power & Fit Guide

Choosing a chainsaw means matching the guide bar length to your wood diameter, picking the right power source for the job, and prioritizing a saw that fits your build and experience level.

One wrong choice — an oversized bar, too much power, or a saw that doesn’t fit your hands — turns a straightforward yard task into a dangerous fight with the tool. The fix is a systematic decision based on three variables: the size of the wood you cut, the access you have to power, and your own physical strength. This guide walks through each one in order, so you end up with a saw that feels right on the first cut.

Start With the Wood Diameter

The single most important spec on a chainsaw is the guide bar length — the metal rail the chain rides on. It directly determines the largest log you can cut in a single pass. Pick the bar length first, and the rest of the saw follows from there.

• 10–14 inches (short bar): Best for pruning, limbing, clearing small branches, and cutting pieces up to 10 inches thick. These are light enough for ladder work and easy for a beginner to control.
• 16–18 inches (medium bar): The sweet spot for firewood, medium trees, and general yard work. If you’re cutting 12-inch logs, a 16- or 18-inch bar is ideal.
• 20 inches and up (long bar): Required for large trees, storm cleanup, and professional forestry. These are heavy, powerful tools for experienced users.

Oversizing the bar — putting a 20-inch bar on a saw meant for a 16-inch — adds weight and vibration without cutting benefit, and Reddit’s chainsaw community consistently warns that “undersized is better than oversized” for safety and control.

Select the Power Source

The power source determines where you can use the saw, how long it runs, and how much maintenance it needs. There is no single best choice — only the right match for your work pattern.

Gas Chainsaws (Measured in cc)

Gas saws deliver the most power and the longest runtime. Engine displacement is measured in cubic centimeters (cc), and higher numbers mean more cutting force. ECHO and STIHL both recommend matching cc to the task:

• 30–40 cc: Light work, cuts hardwood up to 6 inches thick.
• 45–50 cc: Medium work, covers most homeowner firewood and tree cutting.
• 50–70 cc: Heavy and professional work, cuts hardwood up to 24 inches.

Gas saws need fuel mixing, air filter cleaning, and chain tension adjustments. They are louder and heavier than electrics, but for full-day use or cutting far from an outlet, they are the only practical choice.

Battery Chainsaws (Measured in Volts)

Cordless saws are the lightest option and the easiest to start — no pull cord, no fuel mixing. They are measured by battery voltage:

• 20V: Light duty — pruning, small branches, quick cleanup. Tools like the Black+Decker LCS1020 20V MAX are typical.
• 60V: Heavy duty — firewood and medium trees. The DEWALT DCS670X1 FLEXVOLT 60V MAX is a common example.

Battery life limits runtime, and cold weather reduces performance. But the maintenance is minimal, and the noise is low enough to use in neighborhoods without bothering neighbors.

Corded Electric Chainsaws (Measured in Amps)

The cheapest and simplest option — plug in and cut. Corded saws are light and consistent, but you are limited by extension cord length and the risk of cutting the cord. Best for occasional pruning within reach of an outlet.

Chainsaw Selection Table — Quick Comparison

If you are ready to narrow the field by weight and ergonomics for lighter work, our tested roundup of lightweight chainsaws covers the best portable models that still deliver real cutting power.

Ergonomics — The Fit Factor Most Buyers Ignore

A chainsaw that is powerful on paper but awkward in your hands is dangerous. Backwoods Home Magazine’s guide calls “fit” the most overlooked spec, and professional arborists agree. Check these points before buying:

• The handles must be spaced so you can grip with both hands and still reach the throttle trigger comfortably.
• The saw should balance naturally when held in cutting position — not tipping forward or backward.
• When you finish a cut, the tip of the bar should not drop toward the ground because the saw is too heavy to hold level.

Weight matters here more than most buyers realize. Larger saws generate more vibration and require more physical effort to control, which leads to fatigue faster — and fatigue is a direct cause of kickback accidents. If you are a weekend user, a lighter saw with a shorter bar is almost always the safer choice.

Power Source & Cost Comparison

ECHO’s buying guide notes that choosing a brand with local servicing dealers is a practical consideration — chainsaws need periodic maintenance (chain sharpening, oil filter changes, air filter cleaning), and shipping a large saw for service is expensive and slow. STIHL, ECHO, Husqvarna, and DEWALT are all widely supported in the US.

Three Common Mistakes That Send Buyers Back to the Store

Most new chainsaw owners overshoot their real needs. Here is what trips them up:

• Oversizing the bar: A 20-inch bar on a small saw adds weight and vibration without improving cut quality. The saw becomes harder to control and more dangerous.
• Oversizing the power: Buying a 60cc saw to cut 6-inch logs is unnecessary. You carry extra weight and pay for fuel you do not need.
• Ignoring weight: A heavy saw that fatigues you in the first 20 minutes is a saw that will sit in the shed. Buy for the work you actually do, not the work you imagine.

Decision Checklist — Your Final Step

Walk through these questions in order, and the right saw becomes obvious:

• What is the thickest log I will cut? → Add 2 inches — that is your minimum bar length.
• Do I need to work far from an outlet, or all day? → Choose gas.
• Is quiet operation and instant start more important than max runtime? → Choose battery.
• Am I a weekend user doing pruning and small cleanup? → A 10–14 inch corded or 20V battery saw is plenty.

STIHL’s own guidance sums it up: the right bar length, the right power source for your access to electricity, and good ergonomics that match your grip and strength will keep you safe and efficient — and your chainsaw will be a tool you reach for, not a burden you avoid.