AltTuningLab

Calculated starting set

Drop C String Gauges for a 25.5-Inch Guitar

Drop C lowers every string by a whole step and the sixth string one more step. A balanced setup needs to address the low C while keeping the three plain strings playable.

Tuning
C G C F A D
Strings
6
Scale length
25.5 in

Recommendation

.011–.054 is the calculated starting point

Start with .011–.054 on a 25.5-inch guitar. It is a useful middle ground for a low C that needs definition without turning the upper strings into a noticeably heavy lead set.

Tension table

Estimated tension at 25.5 inches

Calculated from pitch, gauge, scale length, and a plain or wound construction estimate.

Total pull93.0 lb
Average / string15.5 lb
Set spread4.8 lb
StringPitchGaugeBuildEstimated tension
6C2.054wound13.5 lb
5G2.042wound18.3 lb
4C3.030wound16.6 lb
3F3.018plain14.8 lb
2A3.014plain14.2 lb
1D4.011plain15.6 lb

Low-string comparison

Compare nearby gauges at the same pitch

The calculator holds C2 and 25.5 inches constant, then changes only the wound low-string gauge.

.052
12.5 lb
.054 Starting point
13.5 lb
.056
14.5 lb

What it should feel like

Use the table to make a confident adjustment

The .054 low C is the decision point. Go to .056 if the lowest string feels loose under a heavy pick, or down to .052 if you prefer a softer attack. The rest of this set tracks the lowered tuning rather than simply making every string heavier.

Before restringing

Plan for the full guitar setup

  1. 1Widen the nut slot only when the new string binds; have a technician do this if you are unsure.
  2. 2Re-check intonation and action after the instrument settles.
  3. 3A 24.75-inch guitar may need a heavier low string than this starting point; calculate using its actual scale length.

Common questions

Drop C string-gauge FAQ

Are .010s too light for Drop C?
A full .010 set often leaves the low C loose on a 25.5-inch guitar. A .054–.011 set gives more support at the bottom while remaining manageable at the top.
Should I use a baritone guitar for Drop C?
Not necessarily. A 25.5-inch guitar can work well in Drop C with an appropriate setup. A longer scale changes the feel and may let you use a lighter low string for similar tension.