Baritone guitar string gauges by scale length: 27, 28.625, and 30 inch compared

Every baritone question comes down to one physical fact. As Stringjoy puts it in its own scale-length explainer, "the tension on any given string on your guitar is a product of the scale length, the tuning, and the mass of that individual gauged string." (Stringjoy) A baritone stretches two of those three variables at once: the scale is longer than a standard guitar's 24.75 to 25.5 inches, and the tuning sits a fourth or fifth lower. Both changes want a heavier string. Get the gauge wrong and a baritone either flops under the pick or fights you on every bend.

The good news is you do not have to guess. Real baritone sets exist at real gauges, and the difference between a 27-inch baritone and a 30-inch one is small and predictable. Ernie Ball's own Baritone Slinky, a .013 to .072 nickel-wound set, is the reference point for most of this guide: Ernie Ball builds it "optimal for A-A or B-B tuning combinations," and it is the one set that covers both of the tunings below without a change.

A 27-inch scale is the most common length guitars are built and marketed as "baritone," and it is where the gauge math is best documented. D'Addario builds its EXL158 Light Baritone set at .013 to .062 nickel wound specifically for shorter-scale baritones in B standard (B-E-A-D-F#-B); D'Addario's own tension chart confirms the B-to-B pitch and totals 138.7 lbs across the set, and our own full EXL158 review breaks down the spec sheet and sourcing. It is the same low-string logic as the standard-scale B standard tuning guide, just applied across all six strings instead of seven.

27 inches is also a real, working scale length, not just a catalog spec. Stephen Carpenter of Deftones has played an ESP STEF B-8, a 27-inch baritone-scale 8-string, as his primary guitar since 2010's Diamond Eyes. His instrument is an 8-string rather than 6, but the scale is the same one most 6-string baritones ship with, and it is long enough to keep a low string playable at B standard tension without resorting to extreme gauges.

Move past 27 inches and the string does not need to change, the tension budget does. Per Stringjoy's own rule of thumb, moving from a 25.5-inch baseline "up to about 26, 26-1/2, or 27 inch scale length, you'll want to go about a half gauge down in order to match the same tension at the same tuning," and "if you get all the way up to something like a 28-inch scale length or more, you'll want to go a whole gauge down." (Stringjoy) Applied to a baritone, that rule runs in reverse: the extra length past 27 inches gives you spare tension, so you can either keep the same .013 to .062 gauge for a firmer feel with more headroom, or size down for an easier-playing instrument at the identical pitch.

A 28.625-inch scale splits the difference between 27 and 30. It behaves like the 30-inch case in miniature: the same gauge that works at 27 inches carries a bit more tension here, enough that some players size down half a gauge for comfort. 27-inch baritones are the ones you will see most often at retail, so before you shop for strings, confirm your own guitar's actual scale length against its spec sheet rather than assuming "baritone" always means 27 inches.

Scale length is only half the equation. The other half is how low you tune, and a 6-string baritone has three real options.

Drop A on a baritone is easy to confuse with Drop A on a 7-string, since both put a low A under the rest of the tuning, but they are not the same instrument or the same gauge problem. 7-string Drop A (A-E-A-D-G-B-E) drops the 7th string of a seven-string guitar; see our Drop A tuning guide for that version and its own gauge targets. Baritone Drop A only touches one string on a six-string neck, so the top five strings can stay at B-standard weight while the low string alone steps up toward A-standard weight, the same logic as adding one heavy wound string to a standard-scale Drop D set.

If what you actually want is the low, tight sound of B standard rather than a 27-inch neck specifically, you can get most of the way there on a guitar you already own. A heavy 25.5-inch-scale set holds C standard and a usable B standard without a baritone at all.

The set we reach for here is Ernie Ball's Not Even Slinky Cobalt, a .012 to .056 six-string set. The cobalt wrap keeps the low strings articulate under gain instead of turning woolly, which matters more on a down-tuned standard-scale guitar than it does on a true baritone. Buy Not Even Slinky Cobalt on Amazon. What you give up is the true baritone's extra scale length: the very lowest notes feel a little looser and less rock-solid than they do on a 27-inch or longer neck, and you cannot reach full A standard this way without the string going slack. For B standard and above, though, it is a fraction of the cost of a second guitar.

The gauges above are the off-the-shelf answers, and they cover the large majority of baritone players. If your instrument sits at an unusual scale length or you want tension dialed in more precisely than "size down half a gauge," custom string makers exist for exactly this. Stringjoy sells guitar singles and sets and, per their own scale-length guide, prefers to handle unusual scale-and-tuning combinations directly: email them your numbers and they will help dial in a set. Kalium sells electric guitar singles, parallel sets, and multiscale sets through its own catalog, built to whatever length and gauge your instrument actually needs rather than a fixed retail spec.

Custom ordering costs more than a packaged set and takes longer to arrive, so it is worth trying an off-the-shelf set first. Most baritones, at any of the three scale lengths above, will play well on one of the sets already covered in this guide.

Start with D'Addario's EXL158 (.013–.062) if your baritone is 27 inches and tuned to B standard. For a longer traditional scale like a Danelectro, still in B standard, D'Addario's EXL157 (.014–.068) steps up to match. For true A standard, at any scale from 27 to 30 inches, Ernie Ball's Baritone Slinky (.013–.072) is the set actually built for it. Longer 28.625-inch and 30-inch necks can run the same gauges as a 27-inch baritone for extra firmness, or size down for an easier-playing instrument at the identical pitch. The Baritone Slinky is the one set to buy first if you are not sure which tuning you will settle on.