Acoustic courses / paired strings

12-String Acoustic Guitar Strings Guide

Understand twelve-string acoustic tuning, octave courses, common gauges, total tension, restringing order, and setup considerations.

By Guitar String Tension CalculatorReviewed 2026-08-09

A twelve-string guitar uses six paired courses. The highest two courses are normally unison pairs, while the lower four combine a fundamental string with a lighter octave string. Gauge planning must consider both the feel of each course and the total pull of all twelve strings.

Start here

Key takeaways

  • The E and B courses are normally unisons; the G, D, A, and low-E courses normally use octave pairs.
  • A factory reference for modern Taylor acoustic twelve-strings is a light .010–.047 set.
  • Use a set intended for twelve-string acoustic guitar and follow the instrument maker’s gauge limit.
  • Record the existing course order before restringing because octave-string placement can vary.

How to use this: Use these recommendations to compare options, then check the final set against the string maker's specifications and confirm that it suits your instrument.

Tuning and string order

From the first course to the sixth, standard tuning is E4/E4, B3/B3, G3/G4, D3/D4, A2/A3, and E2/E3. The physical octave-string position can vary by manufacturer and player preference, so record the existing bridge and nut order before removing a set.

CoursePrimary pitchPaired pitchPair type
1E4E4Unison
2B3B3Unison
3G3G4Octave
4D3D4Octave
5A2A3Octave
6E2E3Octave

Typical light and medium gauge pairs

Twelve-string packaging differs, so read the individual gauges rather than relying only on light or medium labels. Values below are representative starting patterns listed primary/octave or unison partner.

CourseLight pairMedium pairPitch relationship
110 / 1011 / 11E4 unison
214 / 1415 / 15B3 unison
323w / 924w / 10G3 / G4
430w / 1232w / 13D3 / D4
539w / 1842w / 20wA2 / A3
647w / 27w52w / 30wE2 / E3

Gauge numbers are thousandths of an inch. Construction and unit weight determine exact tension.

Managing total tension

Twelve strings can create substantially more total pull than six, even though the octave partners are thin. Use sets intended for twelve-string acoustic guitars and respect the instrument maker’s tuning and gauge guidance.

Some players tune the entire instrument down one or two semitones and use a capo to reduce structural load or change feel. This also changes voice and setup, so it is not required for every healthy instrument.

Restringing and intonation

Change strings in a controlled sequence so each course remains easy to identify. Bring the set up to pitch gradually, stretch gently, and check that every string follows its intended nut and saddle path. Shared or minimally compensated saddles mean octave intonation is always a compromise.

  • Photograph the course order before removal.
  • Protect the top when working with bridge pins.
  • Trim strings only after confirming the winding path.
  • Tune each pair carefully to reduce beating at unison and octaves.

Reference material

Technical references

Use these manufacturer references when you need product-specific tension or setup information. They were last reviewed on ; the gauge suggestions on this page remain starting points because strings and instruments vary.

  1. Twelve-String Courses, Tuning, and Factory GaugeTaylor Guitars
  2. Factory String Gauge ReferenceTaylor Guitars
  3. String Tension Specifications and FormulaD'Addario

Before you change strings

Save your current setup, change one variable at a time, and recheck tuning, neck relief, action, and intonation after the new strings settle. If a result looks inconsistent with your instrument or a manufacturer's data, send the setup details through the contact page.