Why Do New Guitar Strings Keep Going Out of Tune?

Why new strings stretch

A brand-new string hasn’t settled into its length and tension yet. When you tune it up to pitch, the string itself stretches a little. At the same time, the wraps around the tuning post and the end at the bridge get pulled tighter and shift into place. All of that changes the tension between the nut and the bridge, so the note you just tuned slides flat.

That’s why you end up retuning over and over right after a string change. The effect fades as the strings finish stretching. Most of it usually settles down within the first few days, though some sources say it can linger at a smaller level for a few weeks. It depends on the strings and the guitar, so don’t expect an exact schedule.

The direction of the drift is a useful clue. Stretching strings mostly go flat. If a string wanders sharp and flat, or jumps suddenly, the cause is more likely temperature, humidity or something on the guitar itself.

Winding strings properly

Some tuning trouble comes from strings slipping on the tuning posts. A few habits at restringing time make a real difference:

Leave some slack before you start winding so the string wraps around the post several times. Too few wraps can slip; too many can pile up and take longer to bed in.
Wind so each wrap sits neatly below the previous one, without crossing or overlapping.
Keep light tension on the string with your other hand while you wind, so the wraps are snug from the start.

The ideal number of wraps depends on string gauge and post design, so your guitar maker’s or string maker’s instructions are the best guide.

How to stretch new strings safely

Instead of waiting for the strings to stretch on their own, you can stretch them by hand and shorten the settling-in period. Several string makers and gear retailers describe a similar routine:

Tune all the strings to pitch.
Hold one string near the 12th fret and gently lift it away from the fretboard, about a centimeter or two.
Repeat at other spots along the string, such as around the 3rd and 7th frets, so the whole length stretches evenly.
Retune, because the string will have dropped in pitch.
Repeat until pulling on the string barely moves the pitch.

Go easy. Yanking too hard can break a string. Be especially careful with the thin high E and B strings.

Retuning in the first days

Even after stretching, new strings keep moving a little for a while. For the first few days, check your tuning every time you pick up the guitar and once or twice during a session with our guitar tuner. When a string has gone flat, come up to the note from below. Tuning up into pitch helps the string seat itself on the post instead of slipping back.

The tuner shows In tune when the needle sits in the green center. Tuning one string can shift the others slightly, so after you go across all six strings, go around once more starting from the low E. A quick second pass takes less than a minute and saves you from discovering a sour string halfway through your first song.

When it’s not the strings

If tuning still drifts weeks later, or one string keeps going out much more than the rest, look beyond the strings:

Tuning machines. Check for loose posts or worn gears. If a tuner wobbles when you wiggle it, it may need tightening.
The nut. A string that binds in its nut slot sticks and then releases, so it won’t move smoothly when you tune. A pinging sound or a sudden jump in pitch while tuning is a common sign.
The bridge. On an acoustic, make sure each bridge pin is fully seated and the string’s ball end is sitting properly under it.
Temperature and humidity. Moving from a cold room to a warm one, or a change of season, makes the wood and strings shift. This happens no matter how old your strings are.

Jobs like replacing tuners or working on a nut slot are best left to a guitar tech or repair shop. A small adjustment there can save you a lot of retuning.