String gauges for Drop D, Drop C and other low tunings

When you tune down, your strings lose tension, around 11% for every semitone. Most sets handle a half step down fine, but from a whole step down light strings get floppy, they buzz, and the note goes sharp when you pick hard. The fix is to go up in gauge depending on how far you drop.

Why a slack string causes problems

A string’s tension grows with the square of its frequency, so it drops fast when you tune down: a half step loses around 11%, a whole step around 21%, and the low E dropped to C, as in Drop C, close to 37%.

A string with little tension moves a lot more when you pick it, and you’ll notice it like this:

The note goes sharp on the attack and then settles, because picking hard stretches the string too much. On a tuner you see the indicator swing sharp before it settles.
It buzzes: the string swings so wide that it hits the frets.
Chords sound out of tune even though every open string is right, because fretting stretches the string more than usual.
It feels mushy under your fingers and the low end loses definition.

How far to go up in gauge

Gauges are in thousandths of an inch: a 10-46 set has a .010 high E and a .046 low E. To keep the same tension when you tune it down, a string needs to be about 6% thicker for every semitone.

For the low E of a 10-46 set, dropping it a whole step to D calls for about a .052, and dropping it two whole steps to C, about a .058. The math is exact for plain strings and close for wound ones like the low E, so treat it as a guide.

On an electric with a standard 25.5-inch scale, like a Stratocaster, these are common combinations:

Standard tuning: 9-42 or 10-46.
Half-step down (Eb): 10-46 works fine. If you like a firmer feel, 10-52 or 11-48.
Drop D: 10-46 does the job, though the low E feels a bit loose. A 10-52 set, heavier on the bottom and normal on top, firms it up without stiffening the high strings.
D standard (everything a whole step down) and Drop C: 11-50 to 12-56.
B standard: 12-60. Drop B: 13-62, since a 12-60 leaves the low string floppy.
Lower than that, like Drop A, it’s hard to keep sensible tension on a six-string with a standard scale, and most players move to a baritone or a seven-string.

These are ballpark figures. Two players in the same tuning can end up on different sets depending on how much they bend, how hard they pick and how high they like their action.

Scale length matters too

Scale length is the distance from the nut to the bridge. Same note, same gauge: the longer the scale, the tighter the string. A 24.75-inch short-scale guitar like a Les Paul carries about 6% less tension than a 25.5-inch one with the same strings.

So if your guitar is short scale and you’re tuning down, go one step heavier than you would on a long-scale guitar. Baritone guitars, with scales of 27 inches or more, are built to tune very low with sensible tension.

On acoustic and classical guitars

Tuning a steel-string acoustic down won’t hurt it. To get some firmness back you can go up a little in gauge, as long as you don’t go past the tension of the set it came with, which is what it’s built for.

Nylon strings for classical guitar are sold by tension: low, normal or high. For Drop D you don’t need to change anything, and if you’ll spend a lot of time in lower tunings, a high-tension set makes up some of the loss.

Electric bass

Bass works the same way, just with different numbers. A typical set is 45-105:

Drop D and half-step down: 45-105 copes fine. If the E string feels loose, swap it for a .110.
D standard and Drop C: a 50-110 set or a .115 E string.
B-E-A-D on a four-string, or a five-string bass: a low B of .125 to .135. On a four-string you’ll usually need to widen the nut slot for it to fit.

A 35-inch scale gives a firmer low B than a 34-inch one, which is why a lot of five-string basses use the longer scale.

What to check after changing gauge

A different gauge changes the total tension on the neck, and the guitar usually needs some adjusting. You won’t always have to touch everything, but check these:

The nut: a thicker string may not sit well in its slot and can bind. You’ll notice it when the string jumps in pitch as you tune, or goes “ping” and drops out of tune. If that happens, a tech can open up the slot.
The truss rod: with less tension the neck straightens and the strings may buzz on the first few frets; with more tension it bows and the action goes up. A small truss rod adjustment fixes it, and if you’ve never done one, a shop is the safer bet.
Intonation: changing gauge or tuning usually throws the octaves off, so go over it at the bridge saddles.
A floating tremolo: with different tension the bridge tilts forward or back, and the springs in the back need rebalancing.

How to tune in a low tuning

After tuning down, the first pass rarely holds: the neck settles into the new tension, and tuning one string moves the others. Tune, play for a few minutes and tune again. If the strings are new, stretch them first like you would after any string change.

Drop D and half-step down are in the tuner: pick the tuning and follow the indicator string by string. Drop C, D standard and B standard aren’t in the guitar list yet. With Standard selected, a string that’s far from every standard string shows up as a “Free note”, with its name and its frequency rounded to the nearest Hz: enough to check it’s on the right note, but not for fine-tuning. In B standard, the fifth, fourth, third and first strings land on standard notes (E, A, D and B), and the tuner guides them with the indicator as if they were the low E, A, D and B strings.

Frequently asked questions

What string gauge do I need for Drop D?

A standard 10-46 set works, though the low E feels a bit loose dropped to D. If you want it firmer, a set with heavier low strings like a 10-52 gets it back without stiffening the high strings.

What strings should I use for Drop C?

On an electric with a standard scale, somewhere between 11-50 and 12-56. The low E drops two whole steps, from E to C, and loses close to 37% of its tension if you keep the standard gauge.

Do I need different strings to tune a half step down?

No. You lose around 11% of the tension, and most standard sets handle it fine. If you like a firmer feel, go a little heavier, for example from 10-46 to 10-52 or 11-48.

Does changing gauge affect the guitar’s tuning?

Yes, indirectly: it changes the tension on the neck, so the truss rod, the intonation, the nut slot or the tremolo springs may need adjusting. If the guitar won’t stay in tune after the change, check the nut first.

Why does the note go sharp when I pick hard in a low tuning?

Because the string has little tension and picking hard stretches it too much: the note starts sharp and drops as it settles. It’s a clear sign the gauge is too light for that tuning.

Sources

Updated 2026-10-08