The right gauges for any tuning, scale or feel.
"What gauge for Drop C" has one honest answer: the one that gives the same tension you already like. This works that out, string by string, on your scale length.
WHAT IT DOES
- Tension per string from unit weight × (2 × scale × frequency)² ÷ 386.4, with the makers' published unit weights for plain steel (.007 to .026), nickel wound (.017 to .080), phosphor bronze and nickel bass (.040 to .130); in-between gauges interpolated
- Sixteen tunings: standard, drop D, Eb, D, drop C, C, DADGAD, open G, D and E, baritone B, 7-string, 8-string, bass 4, 5 and drop D
- Eleven sets from 9-42 to 13-56 acoustic and 45-130 bass
- Multiscale: each string on its own scale between the treble and bass lengths
- Match mode: pick a reference set, tuning and scale, and it finds the gauge per string that reproduces that tension here; or ask for a flat tension
- Warnings for stiff plain strings, floppy lows, uneven spread, heavy total pull, and setup changes
- Pounds or kilograms; printable set sheet
Who it's for
Players changing tuning, going baritone or 7-string, ordering singles, or building a balanced-tension set.
What you get
- The calculator (one .html file, runs in any browser, offline)
- A 2-page quick-start guide
Good to know
- One file. No install, no account, no subscription, no internet needed after download.
- Your data stays on your computer. Export a backup any time; import it on another machine.
- Works on Mac, Windows, Linux and iPad (open the file in Safari or Chrome).
- Instant download.
What's inside the download
- Guitar-String-Tension-Calculator.html
- Quick-Start-Guide.pdf
Made by Matthew Busel, a one-person studio in Tuckahoe, NY. About me. Questions: support@tensorust.com.
Making and hobbies
Guitar String Tension Calculator
tension per string for any tuning and scale, and the balanced gauge set that matches your feel
Tuning, scale length and gauges in; tension on every string out, with the makers' unit weights for plain steel, nickel wound, phosphor bronze and bass strings. Then tell it the feel you want, your favourite set in standard or a flat 16 pounds, and it picks the single gauge for each string that gets closest on your scale, including fanned frets. Sixteen tunings and eleven sets built in.
Works or I fix it. If a file doesn't open or work as described, email support@tensorust.com within 30 days and I fix it or send a working copy. All sales are final, so check the screenshots or ask first.
- Updated
- Oct 2026
- File
- ZIP, 207 KB: 1 HTML app, 1 PDF
- Who it's for
- Players changing tuning, going baritone or 7-string, ordering singles, or building a balanced-tension set.
One-time price in US dollars, checkout by Stripe. After paying you land on a page with your download link. Each link works for 15 minutes, and reopening that page makes fresh ones.
- Guitar-String-Tension-Calculator.zip