String gauge for any tuning
When you tune down, every string loses tension: a half step down removes about 11%, a whole step about 21%, and the low string in drop C loses more than 35%. The string gets floppy, buzzes and the pitch wobbles on the attack. The fix is a heavier gauge, by the right amount.
Sets that keep the tension of a .010–.046 at 25.5″
D'Addario chart gauges closest to the tension of each EXL110 string in E standard.
| Tuning | Suggested set | kg | lb |
|---|---|---|---|
| E♭ A♭ D♭ G♭ B♭ E♭ | .0105 .014 .018 .028 .038 .049 | 47.2 | 104.0 |
| D G C F A D | .011 .015 .019 .030 .042 .052 | 48.3 | 106.4 |
| D A D G B E | .010 .013 .017 .026 .036 .052 | 46.9 | 103.5 |
| C G C F A D | .011 .015 .019 .030 .042 .056 | 47.9 | 105.5 |
| B F♯ B E G♯ C♯ | .012 .015 .020 .030 .044 .060 | 46.4 | 102.2 |
How to use it
- Choose the instrument and the new tuning (drop C, drop B, whole step down, open G...).
- Choose the reference set: the one you like in standard tuning. Its tension is the target.
- Check the scale length. A 24.75″ guitar needs a slightly heavier gauge than a 25.5″ one for the same tension.
- Read the table: Tension with current string shows how much each string loses; Suggested gives the gauge that brings the tension back.
- Tap Copy suggested set to take the list to the store.
Help and explanations
Tell it the set that feels right to you in standard tuning and pick the new tuning. The calculator uses each string's tension in that set as the target and looks up, in D'Addario's unit-weight chart, the gauge of the same construction that comes closest. From a .010–.046 on a 25.5″ guitar, drop C calls for .011 .015 .019 .030 .042 .056.
Why the gauge has to go up
Tension grows with the square of frequency: T = UW × (2 × L × F)² ÷ 386.4 (D'Addario's formula). For the tension to stay the same on a lower note, the string's unit weight (UW) has to rise by as much as the squared frequency fell. A whole step down, frequency drops to 89% and its square to 79%: the string needs about 26% more weight, which works out to roughly 12% more gauge.
The calculator doesn't invent strings: it picks from the gauges that exist in the D'Addario chart, in the same construction as the original (plain steel, nickel wound, bronze wound, bass). That's why the suggested tension comes close to the target but is rarely identical.
Popular tunings
Drop D only changes the 6th string (a whole step down) and nearly always works with your usual set. Drop C (C G C F A D) drops everything a whole step and the 6th one more: .011–.056 or .012–.056 sets are common. Drop B (B F♯ B E G♯ C♯) already calls for .012–.060 or heavier on a 25.5″ scale, and many players move to a baritone scale or a 7-string.
On bass, drop D and half step down work with a regular set; low B or low A tunings call for a .125 to .135 low string and, ideally, a 35″ scale.
After the change
A heavier gauge fits tighter in the nut slot: make sure the string doesn't bind while you tune. The different total tension also changes neck relief, so check string height and the intonation of each string. To change only the tuning, without new strings, the guitar tuner has drop and open tunings ready to go.
Tips
- If the suggested tension overshoots the target, take the next gauge down: a slightly slack string bothers you less than a binding nut slot.
- In drop C, many players keep the three plain strings from their usual set and only change the three wound ones: the table shows whether that's worth it.
- Set the intonation of each new string with the intonation checker.
- Want the whole set's tension and a comparison between two sets? Use the string tension calculator.
Frequently asked questions
What string gauge for drop C?
To keep the tension of a .010–.046 at 25.5″, the D'Addario chart gives .011 .015 .019 .030 .042 .056. Off-the-shelf 11–56 sets come close. On a 24.75″ scale, the same gauges end up about 6% looser.
Do I need new strings for drop D?
Usually not: only the 6th string drops a whole step and loses about 21% of its tension. If it buzzes, swap just that string for a .049 or .052.
What gauge for D standard (a whole step down)?
Go up about one gauge on every string: if you use .010–.046 in E standard, .011–.052 in D standard (D G C F A D) gives similar tension.
What strings for drop B on a 6-string?
On a 25.5″ scale, something like .012 .015 .020 .030 .044 .060. The 6th string alone needs a .060 to match the tension of a .046 in E.
Does it work for acoustic and bass?
Yes: choose the instrument and it uses strings of the same construction (bronze wound on acoustic, nickel wound on bass). Classical strings are sold by tension, so the suggestion appears as a string from another set.