How to Measure a Chainsaw Bar (Blade) and Chain Length

Need to know how to measure a chainsaw bar?

Maybe you are looking to replace your chainsaw bar (blade) or chain?

But you’re not sure what size it takes?

If so, I can help.

I’ll show you the easiest methods for how to measure a chainsaw bar and how to measure a chainsaw chain length.

These tips are perfect for anyone who has lost their product manual or have had the stamped measurements wear off the side of the chainsaw blade.

I’ll first answer, “How do you measure a chainsaw bar?”, then move onto “How do you measure a chainsaw chain?”

Let’s get started.

Are You Replacing Parts on an Older Chainsaw?

If you’re reading this post and replacing the bar or chain on an older chainsaw, then you may want to check out my other guide on the best budget chainsaw options.

A new bar or chain can cost around $20 to $50 each (or $40 to $100 in total).

If you put that money into a newer chainsaw, it’ll come with those parts already installed. You may also get a better chainsaw all together.

So, take a look at that guide when you have a chance. At the very least, it’s something worth considering.

Or, if you want to see what else is available, I also have a post on the top chainsaws. It includes 10 of the best chainsaws separated by type: gas, electric, and battery powered.

How to Measure a Chainsaw Bar (Blade) Length

Here’s the thing…

Not all chainsaws can handle all bar lengths.

Longer bars require more engine power.

That’s why electric chainsaws can’t use anything longer than an 18-inch blade because their motors lack the power to drive a longer bar and chain.

Some gas chainsaws, on the other hand, can go up to a whopping 72 inches in bar length because they have the beefy engines to handle it.

Another thing to keep in mind is that chainsaw chains don’t stretch. Each one is designed to fit on a certain size bar. For example, if the chain is too short or too wide for the blade, it won’t fit.

But don’t worry.

I’ll explain how to measure a chainsaw blade next so you can get the perfect replacement part.

When shopping for a chainsaw bar, there are two measurements you’ll want to walk into the hardware store with: effective length and true length.

Effective Cutting Length (Or Called Length)

The easiest chainsaw bar measurement you can find is called the “effective cutting length” or “called length”.

The effective cutting length is the span of the bar from the tip of the blade to the base of the where it’s attached to the chainsaw.

To measure this called length, just take a tape measure and start at the base of the blade and then stretch it out to the tip. Whatever measurement you get here, round it up to the nearest even number in whole inches.

For example, if the effective cutting length for your tool measures 18 1/2 inches, then rounding up to the nearest even number would we 20 inches (19 is an odd number so that wouldn’t be correct).

Here’s another example, if the measurement is 15 3/4 inches, then the rounded up called length would be 16 inches.

True Length

The second way for how to measure a chainsaw bar length is called the “true” length of the blade.

As the name suggests, the true length is the actual full length of the bar from tip to end without being installed.

To get the true length measurement, you’ll need to remove the blade from the chainsaw by unscrewing the bolts that hold it in place. These bolts are located on the right side of the chainsaw body just past the base of the bar.

Once the chainsaw blade is removed, lay it flat on the ground (or table).

Then, measure the distance from end to end and don’t round up. Since this is the true length of the blade, there’s no need to adjust the measurement.

Getting a Replacement Chainsaw Bar

Now that you know how to measure a chainsaw blade length, you can take those two measurements (effective cutting length and true length) and go shopping for a replacement part.

Just find a blade that has those two measurements and you’ll have a perfect match.

How to Measure a Chainsaw Chain Length

Measuring a chainsaw chain is a bit tricker than the bar.

You can’t just walk into a store and pick up a chain that matches the effective cutting length of of the blade. General chain lengths, like 18 inches, are not interchangeable.

That’s because chainsaw chains actually have three measurements: number of drive links, pitch, and gauge.

The proper way for how to measure a chainsaw chain length is as follows:

• Count the drive links — Count the individual links on the chain one by one.
• Measure the pitch — This is the distance between each drive link. Measure the length between any three rivets. The rivets are what hold the drive links together. Then divide by 2 to get the pitch. Common pitch sizes include 1/4″, .325″, 3/8″, and .404″.
• Measure the gauge — This is the width of the groove on the chain that fits on the bar. Common gauges include .043″, .050″, .058″, and .063″. You can use a tape measure to find this measurement on the chain itself or use this simple trick using the bar:
  • Grab a quarter, dime, and penny.
  • Try to slide each coin into the groove of the blade. Whichever one fits snugly without force will tell you the gauge of the bar.
  • Quarter = .063″, Dime = .058″, and Penny = .043″

A Chain Measurement Secret…

Now that you know the steps for how to measure a chainsaw chain, I’ll now let you in on a little secret.

Your current chainsaw bar is likely to have all of the measurements you need for a chain replacement stamped right on the blade itself.

These numbers are located on the end of the bar that’s hidden behind bolted cover on the chainsaw body.

If you take the blade off, you should discover a small printed set of numbers near the end. This information will include everything you need to find a matching chain.

For example, it could read something like this: 3/8″ 72 1.3mm/.050″

And you now know what each of those numbers mean: 3/8″ pitch, 72 drive links, and .050″ gauge.

Take those numbers into a hardware store and you’re guaranteed to find a matching chain for your chainsaw bar.

Never Guess the Lengths for Your Chainsaw

As you learned in this guide, it’s a fairly simple process for how to measure a chainsaw bar length and chain.

You should never try to guess what those numbers are.

Doing so could cause you to install a bar or chain that’s not meant to be used on your chainsaw, and that could lead to damaging your tool, or worse, causing an injury during operation.

Fortunately, with the information you learned here, you no longer have to wonder how do you measure a chainsaw bar or chain because you now know how to do it.

As a reminder, if you’re interested in seeing what cheap chainsaws are available to upgrade your existing tool, take a look at my other guide on the best budget chainsaw options. It’s packed with the top chainsaws you can buy for the lowest prices.

Or see what else is available, regardless of price, in my post on the top chainsaws. That page includes the best of the best when it comes to high-quality chainsaws.

Happy sawing!

Your Pal,
Chainsaw Larry