Rex says
Everyday utility math — the kind you'd otherwise pull up four browser tabs for. I keep it to one clean answer.
Try a scenario
Click to load — tweak from there.Inputs
Result
String tension
16.31
Unit weight used (lb/in)
0.00002
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One click, a permanent link with your numbers baked in.
How to use this
- 1Enter string gauge (in (thousandths, e.g. 0.010)).
- 2Enter unit weight override (lb/in, 0 = auto plain steel estimate).
- 3Enter scale length (in).
- 4Enter target pitch frequency (Hz).
- 5Read your string tension on the right — it updates as you type.
- 6Hit Share to keep the scenario or send it to someone.
About this calculator
String tension — not just gauge — determines how a guitar feels to play and how it stays in tune, and the same gauge string feels completely different at a 24.75-inch scale versus a 25.5-inch scale, or tuned down a whole step. This calculator uses the standard string tension formula based on unit weight (from gauge and material), frequency of the target pitch, and scale length, giving you the pull force in pounds so you can match tension across a full set or compare setups before restringing.
Worked example
Using the values the calculator loads with:
Inputs
- String gauge: 0.01 in (thousandths, e.g. 0.010)
- Unit weight override (lb/in, 0 = auto plain steel estimate): 0
- Scale length: 25.5 in
- Target pitch frequency: 329.63 Hz
Results
- String tension: 16.31
- Unit weight used (lb/in): 0.00002
What each field means
Inputs
- String gauge (in (thousandths, e.g. 0.010))
- The string gauge used in the calculation, measured in in (thousandths, e.g. 0.010). Starts at 0.01 in (thousandths, e.g. 0.010) so you have a working example on load. Accepted range: 0.007–0.06 in (thousandths, e.g. 0.010).
- Unit weight override (lb/in, 0 = auto plain steel estimate)
- The unit weight override (lb/in, 0 = auto plain steel estimate) used in the calculation. Starts at 0 so you have a working example on load.
- Scale length (in)
- The scale length used in the calculation, measured in in. Starts at 25.5 in so you have a working example on load. Accepted range: 15–30 in.
- Target pitch frequency (Hz)
- The target pitch frequency used in the calculation, measured in Hz. Starts at 329.63 Hz so you have a working example on load. Accepted range: 40–1000 Hz.
Results
- String tension
- Returned as a decimal number and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Unit weight used (lb/in)
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
Why does scale length matter so much for tension?
Tension scales with the square of both scale length and frequency, so a small change in scale length shifts tension a lot — a Gibson-style 24.75-inch scale needs noticeably heavier gauge strings than a Fender-style 25.5-inch scale to hit the same tension and feel at standard tuning.
What's a comfortable total tension across a set?
Most electric guitar sets land around 80-95 lb total tension across six strings at standard tuning; acoustic sets run higher, often 160-180 lb, because they need to drive the top of the guitar. Going well outside these ranges changes neck relief and can require a truss rod adjustment.
Why does the calculator need a unit weight override for wound strings?
Wound strings (typically the lower four on a guitar) have a steel core wrapped in another metal, so their mass per inch doesn't follow the simple solid-steel-cylinder formula used for plain strings. String manufacturers publish exact unit weight tables for wound gauges — use those numbers in the override field for accurate results.
Accuracy and limitations
- Estimates assume standard, average conditions — local rules, pricing, and materials vary.
- Results are rounded for readability; add a buffer before ordering, booking, or committing.
- Double-check anything with a real cost attached against a local quote.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Guitar String Tension Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/guitar-string-gauge-tension
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/guitar-string-gauge-tension" target="_blank" rel="noopener">Guitar String Tension Calculator — RevenueLab</a> (2026).</p>
Source: [Guitar String Tension Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/guitar-string-gauge-tension) (2026).