How to Measure a Chainsaw Bar and Chain the Correct Way

Last Updated on October 9, 2022 by Barry Gray

Purchasing a new chainsaw bar requires that you have the perfect fit. I can’t tell you how many times I purchased one, only to find it didn’t suit the job. I bought the wrong chainsaw bar once, and it damaged the chainsaw pretty badly, and I got bruised too. You don’t want the same thing to happen to you! 

The best way to measure a chainsaw bar is through two methods. The first one is called measuring the cutting length. The second technique is not that common, but equally useful. It is called measuring the true bar length. The second technique requires absolute precise measurements. Based on this, there is no way to round this number up.

How to Measure a Chainsaw Bar?

chainsaw bar inside the chainsaw

Before you start measuring a chainsaw bar, there are a few pointers to bear in mind:

  • Chainsaws are sold in what are called even numbered lengths.
  • The length depends on the length of the chainsaw bar.
  • The chainsaw bar or blade is the metallic arm that provides support to the chain while cutting.
  • If you buy a 16 inch chainsaw, you are buying a chainsaw bar with a length of 16 inches.

Length or Effective Cutting Length

measuring chainsaw bar and chain

What is Effective Cutting Length?

The effective cutting length represents the distance from the front of the body of the chainsaw to the tip on the bar. This is where the bar disappears inside the saw. 

How to Measure Effective Cutting Length?

  • Place any tape on the bar tip.
  • Measure back to that point of the bar entering the chainsaw body.
  • Round this measurement to the closest even number.
  • If it’s a fraction or odd number, you need to round it to an even number.
  • This is because chainsaws are sold in even numbers.
  • As an example, if the length is 15 inches, round it to 16 inches. If it’s 18 and three quarter inches, round it to the next even number, 20 inches.

True Bar Length

This is a less common method to measure the chainsaw bar length. Here are the steps to do this:

  • Loosen up the bolts holding the bar onto the chainsaw body.
  • Take out the bar, place it over a flat surface.
  • Measure this bar from one end to the other. 
  • This is a precise form of measurement. Pertaining to this, there is no need to round this number up.

How to Сheck the Bar Groove Gauge?

chainsaw bar and chain

You also need to measure the gauge of the bar groove on your chainsaw. Here are the steps to do it:

  • Take a dime, a penny, and a quarter.
  • Insert each of the coins, at a time, into the groove.
  • See which coin fits the groove the best.
  • You can use close approximations for the measurement.
  • For example, 0.063 inches would represent a quarter.
  • 0.058 inches would represent a dime. 
  • 0.043 inches would represent a penny.
  • It is helpful to buy an inexpensive gauge. It helps to measure the chain gauge, chain pitch, as well as file size.

How to Measure the Chainsaw Chain?

getting ready to measure chainsaw chain

Things to Note:

  • Always get a replacement based on the model number and manufacturer.
  • Precision is key here. Even similar lengths will vary depending on the manufacturer.
  • Engraving the numbers on the bar of the chainsaw and chainsaw body is a good practice.
  • This engraving can showcase the number of total driver links, chain pitch, and chain link gauge. 

Measure Chain Pitch

The chain pitch is the distance across chain links. Here are some ways to measure it:

  • Take a measuring tape or ruler.
  • Measure the distance between the three rivets on the chain.
  • Divide this number by two.
  • The final number is the chain pitch.
  • Common pitch measurements include quarter inch, three-eighth inch, and so on.

Measure Driver Links

chainsaw measuring driver links

This process is as easy as counting available links on the chain. Here’s how to do it:

  • Identify links on the driver chain.
  • They usually appear as small bumps on the inner side of the chain.
  • Check the number of links available on the chain.
  • This number is the measurement.

Measure Chain Link Gauge

The chain link gauge is the thickness on the drive links. If the gauge measurement matches the gauge on the chainsaw bar, the chain is a snug fit. You can use multipurpose gauges or calipers to measure this.

Here are the steps to measure the chain link gauge:

  • Place the gauge or caliper alongside the groove.
  • Place it at the location where the chain fits onto the bar.
  • Note down the reading on the gauge or caliper.
  • Common measurements are 0.043 inches, 0.050 inches, 0.058 inches, and so on.

Sizing Guide for Chainsaws (What are the available sizes and how to choose?)

chainsaw on lumber


The type of chainsaw will determine its size. Common bar sizes range between 12 and 20 inches. Furthermore, some of the professional variants arrive in sizes as large as 72 inches. If the bar is longer, the chainsaw is also going to be heavier. 

Best practices

  • Measure the thickness of whatever item you will be cutting.
  • Get a chainsaw bar that is two inches longer compared to this item’s thickness.

Gas powered chainsaws

  • Gas powered chainsaws begin at 16 or 18 inches, but can be as large as 72 inches.
  • The 16 or 18 inch chainsaws are great at cutting medium sized trees.
  • Chainsaw bars that are 20 inches or larger are great at cutting firewood, or large trees.

Electric chainsaws

  • Electric chainsaws are smaller, often 14 or 16 inches.
  • 14 inch saws are great at cutting small trees.
  • 16 inch saws are great at cutting medium trees.

Battery operated saws

  • Battery-operated saws are available in 16 or 18 inches.
  • They are good for cutting medium sized trees.

Smaller battery operated saws

  • Smaller battery-operated saws are available in 6 or 9 inches.
  • You can use these to prune small limbs of trees.

Replacement and Correct Parts

You can make use of a calculator to easily find a replacement for a chain or bar already used.

In case of wanting other options, such as laminated bars that are resistant to corrosion, you can find a professional company that provides parts replacement.

In addition to this, knowing how to measure the chain and bar is the first step to finding a proper replacement yourself. 

Photo of author

Barry Gray

Hi, I’m Barry. I’ve loved woodworking and bringing things back to life for more years than I care to remember. I hope my passion for tools comes across loud and clear in everything you read here on The Tool Square.

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