I recently took out my old childhood Fender squier to hopefully fix it up and begin playing it again. This guitar hadn't been strung, worked on or played since about 2007. I restrung it, but after tuning it I noticed it sounded like shit. So, I realized I needed to intonate the guitar. I watched a tutorial and compared the sound of the open string to the 12th harmonic, and according to the tuners, the 12th harmonics were always either wildly flat or wildly sharp... like if I were to try to intonate the guitar I'd have to either bring the saddles way beyond the length of the screw or back past the bridge. So I know something is off, but I know next to nothing about repairing guitars (trying to learn rather than taking it to a shop).

So I gave up on that for the night and started playing my acoustic guitar that I regularly play. It hasn't been strung in a couple years, but it sounds okay when I play along to songs. I thought I'd test out its intonation and also noticed the same thing with my acoustic- it is either wildly flat or sharp.

So I figure I am doing something wrong here and thought I'd ask for advice. Thanks in advance.

  • "compared the sound of the open string to the 12th harmonic" - I think your main problem is that is not at all how to check the intonation of a guitar. Commented Mar 31 at 2:12
  • The tutorials I have been reading have been saying to compare the open string to the 12th harmonic- that if the guitar is intonated, they will match "If, using an accurate tuner, the string is found to be in tune both when fretting it at the 12th fret and when sounding its 12th-fret harmonic, the string is correctly intonated and you’re in good shape. The string is in tune “with itself.” - fender.com/articles/maintenance/intonation-101
    – brooke
    Commented Mar 31 at 2:16
  • "fretting at the 12th fret" is not the same thing as "the open string". You can check intonation by comparing the pitch fretted at the 12th fret with the 12th harmonic, not by comparing the open string to the 12th harmonic. The fretted pitch are the pitches to fix when intonating, not open pitches or natural harmonics. Personally, I never use the harmonics at all, I just use an electronic tuner to check the pitch of fretted notes, usually the 7th and 9th frets, since I don't play as much up at the 12th fret. Commented Mar 31 at 2:21
  • thanks for the tips!
    – brooke
    Commented Mar 31 at 5:09

1 Answer 1


It is important that before you even try and set your intonation you make sure that the truss rod and neck relief are properly set with the guitar under string tension because a poorly adjusted truss rod will affect intonation and make the guitar difficult to play or maybe even unplayable. There are plenty of online resources that show how to do this. In a nutshell, with the guitar in tune, capo the first fret, hold down the E string on the fret where the neck meets the body. There should be the slightest gap between the E string and the fret at the halfway point between the capo and the held fret. If it touches the rod is too tight and if there is a big gap the rod is too loose. Look for a good video for a more detailed explanation on this.

Once that is done, you can try and set the intonation. The Fender website is correct but you are misreading the information there. Use an electronic tuner to tune the 12th fret harmonic. Now compare it to the fretted 12th fret. If the fretted 12th fret is sharper than the harmonic then the string needs to be lengthened by moving the saddle away from the neck and vice versa if it is flatter than the harmonic. After moving the saddle, re-tune the harmonic and repeat the procedure till they match. Do this with all six strings and you should be ok.

  • thank you dude!!
    – brooke
    Commented Mar 31 at 5:09

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