Acoustic guitar string spacing
Martin's D-28 spaces the strings 2-5/32″ (54.8 mm) at the bridge and has a 1-3/4″ (44.45 mm) nut. Taylor quotes 1-1/2″ (38.1 mm) between the outer strings at a 1-3/4″ nut and 2-3/16″ (55.6 mm) at the bridge on its 314ce. Yamaha's FG800 has a narrower 43 mm (1-11/16″) nut and lists an 11 mm string spacing, which only fits the bridge.
Acoustic guitar string positions
Each string's position from the center of the low E, with an equal clear gap between strings: 54.8 mm at the bridge, 38.1 mm at the nut, D'Addario EJ16.
| String | Gauge | Bridge (mm) | Nut (mm) |
|---|---|---|---|
| 6 | .053 | 0.00 | 0.00 |
| 5 | .042 | 11.42 | 8.08 |
| 4 | .032 | 22.58 | 15.90 |
| 3 | .024 | 33.50 | 23.48 |
| 2 | .016 | 44.23 | 30.87 |
| 1 | .012 | 54.80 | 38.10 |
Martin — D-28 Standard Series specifications (bridge string spacing 2 5/32″)
How to use it
- Choose bridge or nut; the outer-string distance fills in (54.8 mm or 38.1 mm). Enter your guitar's own measurement if it differs.
- Keep Equal gap for a nut. For a bridge with evenly drilled pin holes, switch to Equal centers.
- In the radius section, choose 15″ and read the arc height along the board.
Help and explanations
Martin's bridge figure, Taylor's nut figure and a D'Addario EJ16 (.012–.053) set are loaded. The table places every string at the saddle and the nut, and the radius section shows the arc of a 15″ or 16″ board.
At the nut: 1-3/4″ or 1-11/16″
On a 1-3/4″ nut with 38.1 mm between the E strings and a .012–.053 set, equal gap leaves 6.88 mm between strings. Centers run 8.08 mm from the low E to the A and 7.23 mm from the B to the high E, with 2.76 mm from each outer string to the edge.
A 1-11/16″ (42.86 mm) nut, common on older and budget models, is 1.6 mm narrower overall. It feels closer to an electric neck; fingerstyle players often prefer the extra room of 1-3/4″.
At the saddle, and the radius
With equal centers, 54.8 mm at the bridge gives 10.96 mm from string to string; equal gap would leave 10.22 mm of clear space between each pair. Martin's D-28 is 2-1/8″ (53.98 mm) wide at the 12th fret.
Taylor builds its steel-string acoustics with a 15″ fretboard radius; the 16″ that Martin publishes is the radius of the saddle, not of the fingerboard. Across a 1-3/4″ nut a 15″ radius rises 0.65 mm in the middle. Shape the top of the saddle to roughly the same curve so the action stays even from string to string.
Tips
- With a .053 low E, an outside-edge reading runs about 0.8 mm over the center-to-center figure: 38.9 mm across the outside of the E strings means 38.1 mm between centers.
- Lowered the saddle while you were at it? Check the acoustic guitar action.
- Heavier strings need slightly wider nut slots; compare sets in the string tension calculator.
Frequently asked questions
What is the standard string spacing on an acoustic guitar bridge?
Martin's D-28 uses 2-5/32″ (54.8 mm) between the outer strings, Taylor's 314ce 2-3/16″ (55.6 mm). Yamaha lists 11 mm string spacing for the FG800, which works out to 55 mm overall.
What is the string spacing at the nut of an acoustic guitar?
Taylor gives 1-1/2″ (38.1 mm) between the outer strings on a 1-3/4″ nut. With equal gap and a .012–.053 set, that's 6.88 mm clear between strings.
What is the nut width of an acoustic guitar in mm?
44.45 mm (1-3/4″) on Martin's D-28 and Taylor's 314ce, 43 mm on Yamaha's FG800 and 42.86 mm (1-11/16″) on narrower necks.
What fretboard radius do acoustic guitars have?
Taylor uses 15″ on its steel-strings and Yamaha lists 400 mm (about 15.75″) on the FG800. Martin publishes a 16″ radius for the saddle.
Should the saddle follow the fretboard radius?
Roughly, yes. If the saddle is flatter than the board, the middle strings sit lower and buzz first.