How To Lower The Action On An Acoustic Guitar? (9 Step Guide)

Are you wondering how to lower the action on an acoustic guitar?

You've come to the right place!

In my latest YMI guide, you will learn the following:

  • How Do I Know If The Action On My Guitar Is Too High?
  • What Can Cause An Increase In Guitar Action?
  • What Tools Do I Need To Lower The Action On An Acoustic Guitar?
  • How To Lower The Action On An Acoustic Guitar?

And much more!

How To Lower The Action On An Acoustic Guitar? (9 Step Guide)

If you're looking for tips on doing your own guitar setup, you're in the right place.

One of the most profound ways to improve the playability of your guitar is to adjust its action to your personal preferences, and that’s the area we will primarily focus on in this article.

How Do I Know If The Action On My Guitar Is Too High?

If you’re reading this article, there’s a good chance you at least suspect that your acoustic guitar’s action is too high.

Fortunately, there are a few telltale signs that it’s higher than it should be.

You Have A Hard Time Fretting Notes

When a guitar’s action is too high, the strings are physically too far away from the fretboard.

The consequence of this is that you need to exert more effort just to play notes and chords, and especially for beginners, this can cause a lot of problems.

In the short term, these issues can just make your guitar uncomfortable to play. Over time, though they will start becoming a barrier to progress, and may even cause you to stop picking it up altogether.

Your Intonation Is Off

Overly high action can also cause your guitar’s intonation to be off, too. Intonation is the accuracy of your tuning across the full fingerboard range. Your upper frets may play in tune, but the lower frets might be off.

When your action is too high, the strings may be so far off the fretboard that just trying to play a straight note can actually bend them; the pitch will be incorrect, and your guitar will sound terrible

Please note, that if you’re transitioning from electric guitar to acoustic, your action is supposed to be a little higher on the acoustic guitar.

This is because acoustic strings are typically a heavier gauge and need more space to vibrate.

Action issues aren’t just limited to cheap guitars, in fact, some high-end guitars are well known to ship from the factory with high action (Martin in particular).

The difference is, premium guitars have intentionally high actions to allow more room for player preference.

Cheap guitars usually have high action because of hasty finishing practices.

Players who are generally only using open chords, and frequently us a capo may not even notice that their action is too high until they try to play barre chords, which will be extremely difficult to fret. 

Read More >> How Do You Restring An Acoustic Guitar?

What Can Cause An Excessive Height In Guitar Action?

I’ve briefly mentioned that some guitars arrive from the factory with excessive height of action, but what exactly causes your guitar to have a high action?

If it’s a manufacturing issue, it’s usually down to one of three points:

Your Nut Is Too High

At the top end of the guitar neck you’ll find the nut. This is the top suspension point for the strings.

If it’s improperly set, or too high, it will increase the height of the strings over the fretboard and ruin the playability of the guitar

You Bridge Saddle Is Too High

This one is the biggest offender of all! That’s right, chances are, if you’ve got too high an action, your bridge saddle (at the bottom of the strings) is too tall. Fortunately, it’s a pretty straight forward fix.

Your Truss Rod Is Not Properly Adjusted

The final factory caused source of high action is an incorrectly set truss rod. The truss rod is a long pole, usually, metal or graphite, housed within a channel in your guitar’s neck.

Its job is to combat the bow that would form in the neck due to the tension in the strings. If there is too much neck relief, the action will be high.

In addition to issues and characteristics of the guitar from the factory, there is also some environmental/wear and tear factors that can influence the action of an acoustic guitar.

Temperature and Humidity

Like any natural wooden product, an acoustic guitar will feel the effects of changes in humidity and temperature.

These effects are especially prevalent when the changes are sharp and sudden.

I live in Central Florida, so there’s no way you’d catch me taking my acoustic from my air-conditioned house and using it outdoors during the summer, especially during the day time!

Humidity causes the porous wood to absorb moisture from the air, making it expand and swell

Changes in string tension

As pointed out above, the strings themselves put enormous tension on the neck, which can cause bowing, and eventually high action.

Even if your truss rod is set correctly for your normal setup, a change in string gauge can throw things out of whack and increase the relief, and therefore your action.

For example, you’ve played with extra light or light gauge strings, then you decide to mix it up and install some heavy gauge strings.

These heavier strings increase tension even further, which can bow the neck and increase the height of action.

Wear And Tear

Over a period of years, just by pressing down on the frets, they will begin to wear down.

As action is the height of the string above the top of the frets, if the frets are worn down, this will increase the distance from the strings. 

Read More >> How Do You Clean An Acoustic Guitar?

Did you know: The typical action on an acoustic guitar is around 2mm on the high E string and 2.8mm on the low E string. This is much higher than the typical action on an electric guitar.

What Tools Do I Need To Lower The Action On An Acoustic Guitar?

OK, before we dive into adjusting your action, it’s time to gather your tools. 

You’ll need a precision marked straight edge, or if you’re trying to get really accurate (which I always recommend) invest in a proper string action ruler gauge – they’re inexpensive and give a nice visual reference to the suggested 12th fret string height. 

For the actual adjustment, you’ll need sandpaper, a file, needle nose pliers, and it’s helpful to have a regular ruler and a pencil to mark out how much saddle or nut to remove.

If this is a task you’re taking seriously, I recommend picking up a kit like this one from Amazon. It has all of the tools you’ll need for this job and more.

It’s also handy to have spares on hand. In case the worst happens and you take too much off your saddle or nut, you’ll want a replacement. 

Alternatively, you may want to upgrade to something like a Tusq nut or saddle instead of fixing the standard one from your guitar. 

If you’re going to upgrade, remember to check that you’ve got the right kind – the link above is for a generic style saddle, but they may not be compatible with your guitar if you’re playing a Martin or Taylor.

Finally, it’s useful to have shims handy. 

They can be necessary for securing components that don’t get glued in place. StewMac is a great resource for these kinds of parts.

Read More >> How Do You Record An Acoustic Guitar?

How To Lower The Action On An Acoustic Guitar

Before you start, make sure that you have a clear workspace with enough room to maneuver while keeping your guitar stable and your tools handy.

If you’ve read any of my other articles, you’ll know that I often say it’s ok to use your bed to perform basic maintenance, but if there’s any filing involved, there will be dust, and you don’t want that on your bed!

A final word of warning before we get going! If you’re at all uncomfortable or apprehensive about doing this work to your guitar, stop and take it to a guitar tech or luthier.

You don’t want to risk doing permanent damage to your instrument.

Step 1 – Measure Your Action Height

It’s a good idea to measure the current height of your action before making any adjustments. This will give you a rough idea of how much you need to take off the saddle or nut. The ideal action is 2.0mm on the high E string, and 2.8mm on the low E string. If the height is greater than this, proceed with the adjustment!

Step 2 – Remove Your Strings

You’ll need to get your strings out of the way in order to access the bridge saddle and nut. Make sure to keep your bridge pins in a secure place while you’re working on the guitar without strings.

Step 3 – Decide Whether You’re Adjusting The Nut Or the Saddle

Both will lower the action, but you should know that adjusting the nut is a complex job, best left to professionals. 

The saddle offers quite a lot of room for error. Adjusting the nut height, however, requires an incredibly steady hand, as even the tiniest change has a huge impact on the overall playability. 

Especially if this is your first time working on an acoustic guitar, it’s probably better if you try to make adjustments to the saddle.

Step 4 – Check For Shims

Using your pliers gently remove the saddle from the bridge. It may be in quite tight, and could require a little jimmying to work it loose. This is especially true of old guitars that haven’t had the saddle out in a while. 

The action may be higher than necessary because it’s packed with shims underneath.

Before shaving off anything from your saddle, try removing the shims (if any). This will lower the action noticeably. 

If you’re happy with the scope of this adjustment, you can go ahead and restring. 

Step 5 – Check The Neck

If the shims didn’t do the trick, there’s one more thing to check before making permanent adjustments; the neck.

You want to make sure that the neck is as straight as possible (although many acoustics are designed with a small amount of relief by design). 

If you find that it has excess relief, you’ll need to tighten the truss rod. 

As with any screw, a clockwise turn is required in order to tighten the truss rod. Less is more here, so make small adjustments and check results.

If your guitar is new, it probably shipped with an adjuster tool for the truss rod. If it’s an older guitar and you’ve misplaced it, you’ll be able to use a standard Allen key.

Step 6 – Shave The Saddle

In the event that your guitar isn’t equipped with shims under the saddle, or removing shims didn’t have enough of an effect on the action height, you’ll have to make some permanent adjustments.

If you’re looking to take off a specific amount of material from the saddle, mark it with your pencil and ruler.

This isn’t the time for guesswork, and an uneven job will cause even more issues. 

Place your saddle in a carpenters vise with the bottom facing up.

A neat trick here is to only expose the amount of material that you want to remove from it, the vise will act as a guide and prevent you from taking too much off.

If you’re using this method, you can use an orbital sander.

If you don’t have an orbital sander or a vise, place your sandpaper on a firm, flat surface and tape it down if you can.

Next, take the saddle and place the bottom end (the side that slots into the bridge) and firmly rub it into the sandpaper. 

You should be as conservative as possible here. A mistake will mean you’ve got to replace the part.

 Some folks prefer removing material from the top of the saddle. 

It boils down to personal preference, but in my opinion, taking it off the bottom is easier, plus the exposed finish remains unspoiled. 

Fortunately, mistakes aren’t too costly here.

Replacement saddles are pretty cheap and widely available, but it’s still better not to waste them!

Step 7 – File The Nut Slots

On the nut, you’ll find 6 grooves for the strings to rest on as they make their way up to the headstock. 

Another method of lowering your action is to deepen these slots with a file. As I pointed out earlier, exercise extreme caution if this is the route you’re taking.

Replacing a nut is a lot more involved than replacing a saddle, so the consequences of getting it wrong are definitely amplified (pun definitely intended).

Taking the edge of a fine file, gently rub it into the nut slots, one by one. With this adjustment, we should be removing fractions of millimeters at a time and checking the results.

Step 8 – Restring And Tune-Up

Once you’re happy (in theory) with the adjustments you’ve made, go ahead and restring the guitar. 

Seeing as you’ve gone to the effort of adjusting the action, it would certainly make sense to treat your guitar to a nice new set of strings right now! 

If you haven’t tried Elixir Nanoweb guitar strings, you’re missing out – grab a set and let me know what you think in the comments!

Using a guitar tuner, tighten the strings to the correct pitch. I still love my trusty Fender FT2 clip on!

You can’t check action properly until your guitar is in tune, so this step is really important.

Read More >> What Are The Best Acoustic Guitars For Recording?

Step 9 – Repeat Step 1

Go ahead and repeat step 1 by measuring your action height again. Remember that numbers aren’t everything here! Play some open chords, play some barre chords, and try out some scales across the fretboard. 

You should find it comfortable to fret the strings in every position, and the guitar should be free of fret buzz.

Even if the measurements are right on the rule of thumb guidance, if it’s not comfortable, you need to lower some more. If this is the case, repeat the above until you get it exactly where you want it to be.

My Final Thoughts On Lowering The Action Of An Acoustic Guitar

It’s easy to be over-prescriptive when it comes to things like the perfect height for guitar action. I mentioned earlier that it should be 2.0mm to 2.8mm, but you may prefer it lower, or you might like it higher.

I know that jazz players prefer a lower action, and it makes sense – they move fast and reach far. 

A high action would make this style pretty much impossible to play. On the other hand, blues players and heavy strummers might prefer a higher action, especially if they’re using heavier gauge strings.

If you do go ahead and use this guide to make your own adjustments to your guitar, just remember to take it slow. 

The majority of guitar players don’t do much beyond changing their own strings, so sanding down important components can seem daunting. Being careful about every step will help ensure that you don’t do any damage.

You’ll know if you’ve taken it too far if you start to experience fret buzz (that annoying buzzing sound caused by the guitar strings contacting the frets further down the fingerboard from where you’re fingering a note or chord. 

If there’s fret buzz on open strings then you’ve really taken it too far!

This is not a quick job, so if you’re going to take it on, be prepared to spend some time adjusting, then checking, and even adjusting again until you get it right. The benefits of taking the time to adjust your action, though, are huge. 

A more playable guitar gets played more, the more you play, the better you get, and the better you get, the more you enjoy playing.

Simon Morgan

Simon Morgan

Simon Morgan is the Lead Guitar insider here at Simon is originally from the UK, and has been playing for over 20 years. He counts Eric Clapton, John Mayer, and B.B. King as his biggest influences. Look for updates and reviews about all the latest guitar gear from Simon as he shares his knowledge and expertise with you.

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Simon Morgan

Simon Morgan

Simon Morgan is the Lead Guitar insider here at Simon is originally from the UK, and has been playing for over 20 years. He counts Eric Clapton, John Mayer, and B.B. King as his biggest influences. Look for updates and reviews about all the latest guitar gear from Simon as he shares his knowledge and expertise with you.


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