Guitar Action: How to Measure & Set It
The playability–buzz trade-off, with the actual factory numbers.
Action is the distance between the bottom of the string and the top of the fret. Lower action is easier to play but buzzes sooner; higher action gives more volume and sustain but needs more finger pressure. Setting it is a ten-minute job once you know the target numbers — and the numbers depend on your guitar.
Set neck relief first
Action depends on neck curvature. If you haven't checked neck relief, do that before touching the saddles — otherwise you'll be back here redoing this. See the setup order guide for why the sequence matters.
The factory specs
Fender and Gibson measure at different frets, so their numbers aren't comparable — don't mix them up.
Strat-style (measure at the 17th fret)
| Setting | Metric | Imperial | Notes |
|---|---|---|---|
| Fender factory spec (both E strings) | 1.6mm | 4/64" | The standard starting point |
| Low action | 1.2–1.6mm | 3/64"–4/64" | Fast playing, light touch — buzz-prone |
| Medium action | 1.6–2.0mm | 4/64"–5/64" | Good all-round balance |
| High action | 2.0mm+ | 5/64"+ | Heavy strumming, slide, max sustain |
Les Paul-style (measure at the 12th fret)
| Setting | Metric | Imperial | Notes |
|---|---|---|---|
| Gibson spec — bass E | 2.0mm | 5/64" | Factory standard |
| Gibson spec — treble E | 1.6mm | 4/64" | Factory standard |
| Low action | 1.4–1.8mm | ~3.5/64"–4.5/64" | Fast playing, light touch |
| Medium action | 1.8–2.2mm | ~4.5/64"–5.5/64" | Recommended starting range |
| High action | 2.2mm+ | 5.5/64"+ | Heavy strumming, slide |
How to measure
- Tune to pitch. String tension changes how the string sits.
- Hold the guitar in playing position — gravity changes the reading if it's lying flat.
- Measure from the top of the fret to the bottom of the string — not from the fretboard surface. Use a string action gauge or a ruler with clear mm markings.
- Measure at the 17th fret for Strat-style, the 12th for Les Paul-style.
How to adjust — Strat-style
Each saddle has two tiny hex grub screws (1.5mm Allen key). Clockwise raises, anti-clockwise lowers. Turn both screws evenly to keep the saddle level.
- Set the low E to 1.6mm at the 17th fret.
- Set the high E to 1.6mm.
- Set the inner strings (A, D, G, B) to follow a gentle curve between the two E heights — the fretboard is radiused (typically 9.5"), so the middle strings sit slightly higher, not level.
- Play-test every string up and down the neck; fine-tune individual saddles.
How to adjust — Les Paul-style
The Tune-o-matic bridge sits on two thumbwheel posts — one wheel per side, no per-string adjustment. The saddle radius profile handles the string curve for you.
- Slacken the strings a little if the thumbwheels are stiff — they can bind under full tension.
- Bass-side wheel: set the low E to 2.0mm at the 12th fret.
- Treble-side wheel: set the high E to 1.6mm.
- Retune and play-test.
Chase feel, not numbers
The specs are starting points. The real target is as low as possible without buzz at your normal playing intensity. Lower gradually and play-test between adjustments. Some acoustic-only buzz when you dig in is normal — if it doesn't come through the amp, it's fine. And if you get buzz everywhere even at spec, the problem is upstream: check neck relief.
No gauge? A few household references help with rough checks: a credit card is 0.76mm thick, a medium guitar pick around 0.7–1.2mm.
Measure it with your camera
GuitarDoc Pro measures action with your phone's camera — calibrate against your own frets, freeze the frame, and get too-high / about-right / too-low feedback against your guitar's spec. Or type in a ruler measurement and it tells you exactly which way to turn the saddles, and how far. One-time purchase, no subscription.
Coming soon to the App StoreMore guides: Setup order · Truss rod & neck relief · Fix fret buzz · Intonation