🔧 Guitar Setup Calculator
Enter your current and target action at the 12th fret and see exactly how much to raise or lower the saddle — no guesswork before you reach for the sandpaper.
🔧 Dial In Your Action
What is a Guitar Setup Calculator?
It converts the action you want at the 12th fret into the saddle height change that gets you there. Because the 12th fret is roughly the midpoint of the string, the saddle has to move about twice as far as the action change you're aiming for — this tool does that arithmetic and tells you which way to go.
Use it to lower a high-playing acoustic, raise a buzzing setup, or plan a saddle adjustment before you start sanding or shimming. Always re-check intonation and tuning after any change, and treat the result as an estimate rather than professional setup advice.
❓ Frequently Asked Questions
How does the guitar setup calculator work?
String action is measured at the 12th fret, which sits near the midpoint of the vibrating string. Because of that geometry, moving the saddle changes the height at the 12th fret by about half as much — so to change the action by a given amount, the saddle must move roughly twice that. Enter your current and target 12th-fret action in millimetres and it returns the saddle height change and whether to raise or lower it.
How do I measure string action?
Fret nothing, then measure the gap between the bottom of the string and the top of the 12th fret with a machinist ruler or string-action gauge, in millimetres. Do it with the guitar tuned to pitch and held in playing position, and measure the low and high E strings separately since they're often set to different heights.
Do I lower the saddle or the nut?
This calculator addresses action at the 12th fret, which is governed mainly by saddle height. The nut affects action low on the neck (first few frets). If the guitar plays high everywhere including open chords, the nut may also need attention, but for 12th-fret action the saddle is the adjustment this tool estimates.
Is this safe to do myself?
Lowering a saddle by sanding its base or raising it with a shim is a common DIY setup task, but it's irreversible if you sand too far, and changing action affects intonation and can introduce fret buzz. Work in small increments, re-check tuning and intonation after each change, and see a qualified tech if you're unsure. This tool provides an estimate, not professional setup advice.