A chainsaw is sized to the wood it bucks, and the honest way to size it is a bar about two inches longer than the log you cut most days, driven by the smallest engine class that pulls that bar without bogging. The five classes below are the 10cc bands the trade already uses; the log diameter beside each is the single-pass cut its typical bar makes.

Gas saws are placed by displacement. Battery and corded saws have no displacement, so they are placed by the bar the maker ships, which is the maker's own statement of what the saw is for: 12 inches and under sits in the 30cc class, 14 to 16 in the 40cc class, 18 in the 50cc class, 20 in the 60cc class. Every battery or corded class on the site is labelled “by bar” so nobody mistakes a placement for a measurement. The catalog runs from the Stihl MS 151 T C-E at 23.6cc to the Stihl MS 881 Magnum at 121.6cc.

Cubic centimetres of engine. It is not horsepower, but in a two-stroke saw it tracks torque closely enough that the whole trade sizes by it. A 30cc saw limbs and cleans up storm damage; a 50cc saw is the firewood answer because it runs an 18-inch bar through hardwood without bogging; 60cc and up is felling and bucking big timber, and the extra power is paid for in weight you hold at arm's length all afternoon.

Two saws with the same displacement can still differ: the pro lines (Stihl's MS 261 and up, Husqvarna's XP, Echo's P models) run higher chain speeds, magnesium cases and better anti-vibration than farm-and-ranch saws of the same cc, which is what the price gap buys.

Kilowatts at the crankshaft, as the manufacturer publishes it. Stihl and Husqvarna print it for every gas saw; Echo prints horsepower (1 kW is 1.34 hp); most battery makers publish nothing, which is why the field is blank on many cordless entries rather than guessed. It is the better number for comparing two saws of similar displacement, and useless across power sources.

Voltage sets the ceiling on power; amp-hours set the runtime. The 70 battery saws here run on 9 platforms (12, 18, 20, 24, 36, 40, 56, 60, 80 V). An 18 or 20 V tool platform saw is a limbing and pruning tool; 40 V covers storm cleanup and light firewood; 56 to 80 V is where a cordless saw matches a 40cc gas saw cut for cut. The kit battery's amp-hours decide how many cuts you get before a swap, and a spare pack costs as much as a budget gas powerhead, which is the real limit on cordless for all-day firewood.

Every battery entry states what its price buys: a kit with a named pack and charger, or the bare tool. The same saw often sells both ways, under two model numbers, at prices $100 or more apart.

The bar needs to run about two inches longer than the log you cut most often, so the tip clears in one stroke without burying it. A 16-inch bar takes a 14-inch trunk in one pass, and with a cut from each side it will get through wood nearly twice its length when the occasional big log shows up. Every detail page prints that single-pass figure as bar minus two.

Longer bars cost weight at arm's length, more chain to sharpen, more bar to oil, and more exposed tip, which is where kickback starts. The bar range a maker rates a powerhead for is recorded separately; fitting a 24-inch bar to a saw rated to 20 is how people end up with a bogged engine and a stretched chain. Bars here run from the Milwaukee M12 Fuel Hatchet 6" Pruning Saw Kit at 6 inches to the Stihl MS 881 Magnum at 36.

Pitch is the distance between three rivets divided by two; gauge is the thickness of the drive link that rides in the bar groove. A replacement chain must match both, plus the drive-link count for the bar, or it will not fit. The catalog's chains come in 6 pitches (3/8" Picco, .325", 3/8" , .404", 3/8" low-profile, 1/4").

Smaller pitch (1/4" and 3/8" low-profile) cuts smoother with less kickback and is what homeowner and top-handle saws ship with; .325" is the farm-saw standard; full 3/8" and .404" take bigger bites and belong on 60cc-plus saws. Sharpening file size follows pitch, so note it before buying files.

This is the spec that goes wrong most often. Manufacturers publish powerhead dry weight: no bar, no chain, no fuel, and for a battery saw no pack. Retailers often publish shipping weight. Neither is what comes off the tailgate. 110 of the 148 saws here state a bare figure and the rest quote a weight that already includes cutting gear or a named battery, so each entry carries its basis next to the number instead of converting between them.

A 20-inch bar, chain and a full tank add several pounds to a mid-size gas saw; a large pack adds more than that to a cordless one. The lightest saw in the catalog is the Milwaukee M12 Fuel Hatchet 6" Pruning Saw Kit at 4.1 lb (tool only, without battery (Milwaukee: under 5 lb with the XC4.0 pack)); the heaviest is the Stihl MS 881 Magnum at 21.4 lb (powerhead only, dry (no bar/chain/fuel)).

67 gas, 70 battery and 11 corded saws. Gas refuels in thirty seconds and cuts all day, at the cost of two-stroke maintenance, pull-starting and fuel that goes stale over a winter. Battery starts instantly and needs nothing but chain oil and a charger, until the second pack runs flat halfway through a cord. Corded is the cheapest cut per hour there is, within a hundred feet of an outlet. The gas-versus-battery guide works through the runtime economics.

One ladder applied across every brand. Homeowner saws are built to a price with clamshell engines and plastic where pro saws use magnesium; farm-and-ranch saws are the 50cc firewood class with better anti-vibration and a real air filter; professional saws are the ones tree crews and loggers run daily, with higher chain speeds and rebuildable engines; arborist saws are top-handle models built for one-handed use while roped into a tree, and a bad idea on the ground. Every guide here says the last part twice on purpose.

Consumer warranties here run from 1 to 5 years. Echo's five-year consumer term is the longest on a gas saw here, matched only by its sibling brand Shindaiwa — EGO, Milwaukee, Ryobi, Kobalt and Worx reach five years on battery tools; Husqvarna extends two years to four if you register and buy its pre-mixed fuel with the saw; Stihl stays at two with a similar fuel offer. Commercial use usually halves the term. None of them covers a carburetor gummed by stale fuel, which is the most common chainsaw failure there is.