What size chain does your saw take?
Pick your saw and the bar actually fitted to it. You get the pitch, gauge, drive-link count, file size and the Oregon-equivalent chain — checked against manufacturer fit-up charts, with the one verification step that keeps you from ordering the wrong loop.
No saw handy? The answer is stamped on your bar. Jump to the bar-stamp verification guide — it takes about a minute with the chain off. The house saw above is always running: tooth spacing is compressed for clarity; a real 72-link loop carries all 72 drive links around this same path.
Why bar-first?
The model name alone does not pick the chain
A chainsaw model is sold with several bar lengths, and owners swap bars all the time. The chain has to match the bar that is on the saw today — its pitch, its groove gauge, and its drive-link count. Get any one of the three wrong and the loop either will not mount, will not seat in the groove, or will run dangerously loose.
This is not a theoretical problem. For the Stihl MS 250 — one of the most common homeowner saws in North America — the top web results currently contradict each other: one roundup lists .325″ pitch / .063″ gauge / 68 drive links, another lists 3/8″ pitch and .050″ gauge, and a marketplace listing gives 62 drive links for a 16″ bar and 72 for an 18″ bar. All three cannot be right for the same saw.
So every lookup on this site works the way a good dealer counter does:
- 01Start with the saw and the fitted bar length — that narrows the spec to the factory combinations.
- 02Check the stamp on your bar tail — pitch, gauge and drive links are stamped into the bar itself. If the stamp and the chart disagree, the stamp wins: your bar may not be the one the saw shipped with.
- 03Order by the three numbers, not by bar length alone — “18-inch chain” is not a specification.
Most looked up
Popular saw models
Stihl MS 170 / MS 180
Stihl's entry-level saws. Stock 16″ setup: 3/8″ Picco low-profile, .043″ gauge, 55 drive links — Stihl 61 PMM3.
See chain sizes →Stihl MS 250
One of the best-selling homeowner saws in North America — and the model where published chain specs contradict each other most. Bar-first verification matters most here.
See chain sizes →Husqvarna 450 Rancher
50.2 cc ranch saw. Stock 18″ setup: .325″ pitch, .050″ gauge, 72 drive links — Husqvarna H30 / X-CUT SP33G.
See chain sizes →Husqvarna 455 Rancher
55.5 cc ranch saw. Factory 20″ setup per Husqvarna's own manual table: 3/8″ pitch, 72 drive links — in both .050″ and .058″ gauge versions.
See chain sizes →Echo CS-400
40.2 cc homeowner saw on 3/8″ low-profile chain. Oregon's data: 16″ bar, .050″ gauge, 56 drive links, 5/32″ file.
See chain sizes →Echo CS-590 Timber Wolf
59.8 cc firewood saw. Echo's manual specifies Oregon 72LPX chain, 3/8″ pitch; the standard 20″ bar takes 70 drive links at .050″ gauge.
See chain sizes →Browse
By brand, bar length or chain spec
Before you order
Three numbers, one stamp
Read the full verification guide → · Open the chain identification chart →
Straight answers
Frequently asked questions
What size chain does a Stihl MS 250 take?
There is no single honest answer, because MS 250s left dealers with different bars — and published sources disagree with each other. Listings we checked report .325″ pitch / .063″ gauge / 68 drive links, 3/8″ pitch / .050″ gauge, and 62 drive links (16″ bar) / 72 drive links (18″ bar). Read the stamp on your bar tail, then match all three numbers. The MS 250 page lays out each reported variant side by side.
How do I know my chain size if I threw the box away?
Read the stamp on the tail of the guide bar (you will need to take the bar cover off — two nuts on most saws). It shows bar length, pitch, gauge and usually the drive-link count. No readable stamp? Count the drive links on your old chain and measure the pitch: distance across three consecutive rivets, divided by two. The verification guide walks through all three methods.
Oregon 72 vs 73 chain — what is the difference?
Same pitch (3/8″), different gauge: 72 is .050″ and 73 is .058″. This is the classic wrong buy in this category — the boxes look identical. A .058″ chain will not seat in a .050″ bar groove, and a .050″ chain in a .058″ groove runs sloppy and can derail. Check the gauge number on your bar stamp before you order. Full code table on the identification chart.
How many drive links do I need?
As many as the bar fitted to your saw was built for — the count is stamped on the bar tail on most bars, and it changes with bar length even on the same saw. A 20″ Husqvarna 455 Rancher bar takes 72 drive links; the same saw on a shorter .325″ setup can take anywhere from 56 to 78 depending on the exact bar. Never order by model name alone.
Can I run a different-gauge chain if the pitch matches?
No. Gauge is the thickness of the drive links, and it must match the width of the groove in your guide bar. A thicker chain will not seat; a thinner one wobbles in the groove, wears the bar rails unevenly and can jump off. Pitch, gauge and drive links all have to match.
What file size do I need to sharpen my chain?
File size follows pitch: 3/8″ low-profile → 5/32″ (4.0 mm); .325″ → 3/16″ (4.8 mm); standard 3/8″ and .404″ → 7/32″ (5.2–5.5 mm). Every model page on this site lists the file size next to the chain spec, and the identification chart has the full table.
More answers in the guides: Oregon 72 vs 73, how to count drive links, file sizes.
What a loop costs
Typical prices (examples)
So the buying sections on our model pages make sense: in listings checked on 23 October 2026, a single Oregon replacement loop was listed at about $21.43, and Oregon 3-packs at about $47.94–$67.99. Echo's own 20″ 72LPX70CQ loop for the CS-590 was listed at $43.99 by a US power-equipment dealer. These are examples from the day they were checked, not live prices — chains are sold by dealers and marketplaces whose prices move. Every price on this site is labelled with the date it was checked.