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Guitar String Tension Calculator

String tension from gauge, scale length, and pitch.

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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

Tension (lb)

1.48

Tension (kg)

0.67

Pitch (Hz)

82.41

Scale length (in)

25.50

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How to use this

  1. 1Enter string gauge (in).
  2. 2Enter scale length (in).
  3. 3Enter target pitch (Hz).
  4. 4Enter unit weight (lb/in).
  5. 5Read your tension (lb) on the right — it updates as you type.
  6. 6Hit Share to keep the scenario or send it to someone.

About this calculator

Changing tunings or scale length shifts tension hard. This estimates pounds of tension per string.

FormulaT = (UW × (2 × L × F)²) ÷ 386.4

Worked example

Using the values the calculator loads with:

Inputs

  • String gauge: 0.046 in
  • Scale length: 25.5 in
  • Target pitch: 82.41 Hz
  • Unit weight: 0.0000323 lb/in

Results

  • Tension (lb): 1.48
  • Tension (kg): 0.67
  • Pitch (Hz): 82.41
  • Scale length (in): 25.5

What each field means

Inputs

String gauge (in)
The string gauge used in the calculation, measured in in. Starts at 0.046 in 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.
Target pitch (Hz)
The target pitch used in the calculation, measured in Hz. Starts at 82.41 Hz so you have a working example on load.
Unit weight (lb/in)
The unit weight used in the calculation, measured in lb/in. Starts at 0.0000323 lb/in so you have a working example on load.

Results

Tension (lb)
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.
Tension (kg)
Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
Pitch (Hz)
Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
Scale length (in)
Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.

FAQ

How does the guitar string tension calculator work?

Changing tunings or scale length shifts tension hard. This estimates pounds of tension per string. The underlying maths is: T = (UW × (2 × L × F)²) ÷ 386.4

What do I need to enter?

4 values: string gauge, scale length, target pitch, and unit weight. Each field starts with a sensible default, so you can change one number at a time and watch the result move.

What does the tension (lb) result mean?

It is returned as a decimal number and updates live as you edit the inputs, so you can compare two or three versions of a scenario in a few seconds.

Is this calculator free, and do I need an account?

Yes, it's free, and no account is required. Nothing you type is stored on our servers — the maths runs entirely in your browser.

How accurate is the result?

It applies the standard formula exactly, so the arithmetic is precise. Estimates assume standard, average conditions — local rules, pricing, and materials vary.

Who is this tool for?

It's built for anyone doing everyday planning maths — a quick estimate that would otherwise need four browser tabs and a calculator app.

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

Model Scale Conversion Calculator

Convert real dimensions to any modeling scale.

Cite this calculator

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APA
RevenueLab. (2026). Guitar String Tension Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/guitar-string-tension
HTML
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/guitar-string-tension" target="_blank" rel="noopener">Guitar String Tension Calculator — RevenueLab</a> (2026).</p>
Markdown
Source: [Guitar String Tension Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/guitar-string-tension) (2026).
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