Tuning a guitar takes ninety seconds once you know two tricks, and most of a frustrating evening if you don't. The tricks aren't secrets — always tune up to the note, and check the whole set twice — but nobody tells beginners why, so the pegs get fought instead of used.
Here's the whole method, plus the honest reasons a guitar drifts out of tune in the first place. Spoiler: it's usually not the tuner and it's usually not you.
1 – Open the tuner, pick Guitar, hit start. Standard tuning is loaded already; the tuner knows which string you're on the moment you pluck it.
2 – Start with the low E and go string by string toward the high E. Pluck near the soundhole, let it ring, and watch the needle — not your hand. Small peg moves. Smaller than that.
3 – Here's trick one: always arrive from below. If a string is sharp, don't ease it down to pitch — drop it clearly flat, then come back up. Tuning upward loads the string against the tuning post and the nut so there's no slack waiting to slip the moment you strum. Tuning downward leaves that slack in the system, and it cashes itself in halfway through your second song.
4 – Trick two: do the whole set again. Six strings pull on one neck. Adding tension to the low strings bows the neck a hair and drops the ones you already did — a fresh tuning is a moving target until the second pass. Round two takes twenty seconds because everything's close.
That's it. Ninety seconds, both passes included, and it holds.
New strings stretch. For the first day or two, fresh strings lengthen under tension and go flat almost as fast as you tune them. Speed it up: tune to pitch, grab each string mid-neck, give it a firm (not violent) pull away from the fretboard, retune. Three rounds of that and they settle. Old strings have the opposite problem — they stop holding a consistent pitch along their length and no amount of tuning fixes corrosion.
Temperature. A guitar that rode in a cold car will drift for ten minutes while the wood and wire warm up. Tune after it acclimates, not before.
The nut pinches. If a string goes "tink" and jumps pitch while tuning, it's binding in the nut slot. A soft pencil's worth of graphite in the slot is the folk remedy, and it works.
Sloppy string winding. Fewer, neater wraps around the post hold better than a bird's nest. Two or three wraps is plenty.
Two cases worth knowing. If the tuner shows a note a semitone off on every string, you're probably in a different tuning than you think — check the tuning selector, and see our alternate tunings guide if you meant to be. And if the low E is shy about registering on a phone, that's physics, not failure: phone mics reproduce 82 Hz weakly. Pluck firmly and let it ring, or tune the string's 12th-fret harmonic instead — same pitch class, twice the frequency, easy for any mic.
Last thing: within ±5 cents, stop. That's tighter than your frets are accurate, and chasing the last half-cent on a peg is how strings break at 11 pm.