In This Guide
1 What Is Guitar Action and Why It Matters
Action refers to the height of the strings above the fretboard, measured at specific fret positions. It is one of the most important factors in how a guitar feels to play. Action that is too high makes fretting notes difficult and tiring, especially for beginners who have not yet developed finger strength. Action that is too low causes the strings to buzz against the frets, producing an unpleasant rattling sound.
The ideal action is a personal preference that varies depending on your playing style, string gauge, and the type of music you play. Fingerstyle players and jazz guitarists often prefer slightly higher action for a cleaner tone and more dynamic range. Rock and metal players tend to prefer lower action for faster fretting and easier bends. Most players fall somewhere in the middle.
Factory action settings on new guitars are usually set to a moderate height that avoids both excessive buzzing and extremely high strings. However, these settings are generic and may not suit your individual preferences. Learning to measure and adjust your action is one of the most practical skills you can develop as a guitar owner, and it is part of a proper guitar setup.
Action is controlled by several components working together: the bridge saddle height, the nut slot depth, and the neck relief (the slight forward bow controlled by the truss rod). Adjusting any one of these affects the others, so a methodical approach is important. Understanding how these parts interact will make you a more informed guitar owner.
Pro Tip
If you just bought a new guitar and it feels hard to play, do not assume that is just how guitars feel. Many budget guitars leave the factory with action set too high. A proper setup by a technician can transform an uncomfortable guitar into one that feels great, often for less than $50.
2 How to Measure Your Action
To measure action accurately, you need a ruler with fine markings (1/64-inch or millimeter increments) or, ideally, a string action gauge, which is a specialized ruler designed for guitar setup work. These inexpensive tools are available at any music store or online for just a few dollars, and they make precise measurement much easier than a standard ruler.
The standard measurement point is at the 12th fret. Place your ruler or gauge on top of the 12th fret (not in the space between frets, but directly on the fret wire) and measure the gap between the top of the fret and the bottom of the string. Do this for both the low E string and the high E string, as the action is typically slightly different on each side.
Common action height ranges for electric guitars are 3/64" to 5/64" (1.2mm to 2.0mm) on the high E string and 4/64" to 6/64" (1.6mm to 2.4mm) on the low E string. Acoustic guitars generally sit slightly higher, around 5/64" to 7/64" (2.0mm to 2.8mm) on the high E and 6/64" to 8/64" (2.4mm to 3.2mm) on the low E. These are guidelines, not rigid rules.
Also check the action at the first fret by pressing the string at the third fret and measuring the gap between the bottom of the string and the top of the first fret. This gap should be very small, roughly the thickness of a business card or about 0.010" to 0.015". If the first-fret action is too high, the nut slots need to be deepened. This is a precise job best left to a professional unless you have nut files and experience.
3 Adjusting Action on an Electric Guitar
On most electric guitars, adjusting the bridge saddle height is straightforward and requires only an Allen key (hex wrench) or a small flathead screwdriver, depending on the bridge type. Each saddle typically has two small screws or Allen bolts on either side that raise or lower that individual string. This string-by-string adjustability is one of the major advantages of electric guitar bridges.
To lower the action, loosen the strings slightly (you do not need to remove them), then turn the saddle adjustment screws counterclockwise. Most adjustments are very small; a quarter-turn at a time is the right approach. After each adjustment, retune the string to pitch and check for buzz by fretting notes up and down the neck. If you hear a fret buzz, you have gone too low and need to raise the saddle slightly.
For a Stratocaster-style tremolo bridge, each saddle has two tiny Allen screws. On a tune-o-matic bridge (Gibson-style), the entire bridge is raised or lowered using thumbwheels on the mounting posts; you cannot adjust individual strings independently. On these bridges, you adjust the overall height and accept a factory-set radius across the saddles.
After adjusting the bridge saddle height, you will likely need to check and readjust your intonation because changing the string height at the bridge alters the effective string length. You should also verify that the neck relief is correct before making saddle adjustments, because an incorrect truss rod setting can make it impossible to achieve low action without buzz, no matter how carefully you set the saddle height.
Pro Tip
Before adjusting anything, write down your current measurements. If something goes wrong or you do not like the result, you can always return to the original settings. A small notebook dedicated to your guitar's setup measurements is invaluable.
4 Adjusting Action on an Acoustic Guitar
Adjusting action on an acoustic guitar is more involved than on an electric because the saddle is not individually adjustable with screws. On an acoustic, the saddle height is the primary way to adjust action, and lowering it requires physically removing material from the bottom of the saddle. This is a permanent modification, so measure carefully and work slowly.
To lower acoustic action, remove the strings and lift the saddle out of its slot in the bridge. If the saddle is tight, gently wiggle it side to side while pulling upward. Mark the amount you want to remove on the bottom of the saddle using a pencil line. A good starting point is to remove half the amount you want the action to drop at the 12th fret (because the 12th fret is roughly the midpoint of the string length, so the saddle change is effectively doubled at that point).
Sand the bottom of the saddle flat against a piece of sandpaper laid on a flat surface like a piece of glass or a granite tile. Use 220-grit sandpaper and work in straight, even strokes to keep the bottom perfectly flat. Check your progress frequently against the pencil line. It is much easier to remove more material than to put it back, so err on the side of removing too little.
Reinstall the saddle, restring the guitar, tune to pitch, and measure the action again. If it is still too high, repeat the process, removing a small amount at a time. If you remove too much and the action is now too low (causing buzz), you will need a new, taller saddle. Bone and TUSQ saddle blanks are inexpensive and can be shaped with sandpaper and files. For significant action changes or if the nut also needs adjustment, consider taking your guitar to a qualified luthier.
Warning
Never sand or file the top of the saddle to lower the action. Removing material from the top changes the break angle and contact point of the string, which ruins the intonation and can reduce volume and sustain. Always remove material from the bottom to maintain the saddle's original profile.
5 The Relationship Between Action, Relief, and Intonation
Action, neck relief, and intonation are interconnected. Changing one often requires readjusting the others. Neck relief is the slight forward bow in the neck controlled by the truss rod. A small amount of relief is necessary to prevent buzzing in the middle frets, where the string's vibration arc is widest. Too much relief raises the action unnecessarily in the middle positions.
The correct order for a complete action adjustment is: first set the neck relief with the truss rod, then adjust the saddle height, then check the nut height, and finally set the intonation. Working in this order ensures that each adjustment builds on a stable foundation. Trying to lower the saddle without first checking the relief is a common mistake that leads to frustrating results.
If you lower the bridge saddles but still have high action, the neck may have too much relief, which causes the strings to sit high over the middle frets even when the saddle is low. Conversely, if you straighten the neck too much to lower the action, you may get buzzing on frets one through five while the rest of the neck plays clean. Balance is the goal.
Intonation is affected because changing the string height changes the distance the string must travel when fretted, which slightly alters the effective string length. After any action adjustment, check your intonation by comparing the 12th-fret harmonic to the fretted note at the 12th fret. If they do not match, the saddle position needs correction. On electric guitars this is a simple screw adjustment; on acoustics, intonation is set by the saddle's shape and position.
6 Finding Your Ideal Action Height
There is no single "correct" action height. The right setting is a balance between comfortable playability and clean, buzz-free tone that suits your specific playing style. Start with the manufacturer's recommended specifications if available. If not, the standard ranges mentioned earlier in this guide are a reliable starting point.
Lower action makes the guitar easier to play, which is especially important for beginners still building finger strength. However, very low action reduces the dynamic range of the instrument because you cannot dig in as hard without causing fret buzz. Aggressive strummers and heavy-handed players need more room between the strings and frets than someone with a light touch.
The gauge of your strings also affects what action height works. Heavier strings vibrate in a wider arc and need more clearance to avoid buzzing. Lighter strings vibrate in a narrower arc and can be set lower. If you switch string gauges, you may need to readjust your action and possibly the truss rod to accommodate the change in tension.
Do not be afraid to experiment. Make small adjustments, play for a day, and evaluate. Live with each setting for at least a full practice session before deciding if you like it. Your perception of action height changes as your technique develops; what felt impossibly low six months ago might feel perfect now. The important thing is that your guitar feels comfortable and inspires you to keep playing.
Pro Tip
Some fret buzz is only audible when you play unplugged. If you play electric guitar and a tiny bit of buzz is audible acoustically but does not come through your amplifier, you can safely ignore it. Many professional guitarists have action low enough to buzz slightly unplugged because it does not affect their amplified tone.
Key Takeaways
- Action is the string height above the fretboard, measured at the 12th fret; it directly affects playability and tone
- Electric guitar action is adjusted with bridge saddle screws; acoustic action requires sanding the saddle bottom
- Always set neck relief first, then saddle height, then nut height, then intonation, in that order
- Make small adjustments (quarter-turns or thin sanding passes) and check results frequently
- Lower action is easier to play but reduces dynamic range; find the balance that suits your style
- Record your measurements before making changes so you can always restore the original settings