{
  "slug": "guitar-string-gauge-tension",
  "title": "Guitar String Tension Calculator",
  "heading": "Guitar String Tension Calculator",
  "category": "other",
  "url": "https://www.revenuelab.fyi/toolbox/guitar-string-gauge-tension",
  "summary": "Calculate string tension in pounds from gauge, scale length, and pitch.",
  "description": "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.",
  "formula": "Tension (lb) = (UW × (2 × L × F)^2) ÷ 386.4, where UW is unit weight (lb/in), L is scale length (in), F is frequency (Hz).",
  "dateModified": "2026-09-30",
  "run_url": "https://www.revenuelab.fyi/api/public/calc?tool=guitar-string-gauge-tension",
  "inputs": [
    {
      "id": "gauge",
      "label": "String gauge",
      "kind": "number",
      "hint": null,
      "default": 0.01,
      "unit": "in (thousandths, e.g. 0.010)",
      "min": 0.007,
      "max": 0.06
    },
    {
      "id": "unitWeight",
      "label": "Unit weight override (lb/in, 0 = auto plain steel estimate)",
      "kind": "number",
      "hint": null,
      "default": 0,
      "unit": null,
      "min": 0,
      "max": null
    },
    {
      "id": "scaleLength",
      "label": "Scale length",
      "kind": "number",
      "hint": null,
      "default": 25.5,
      "unit": "in",
      "min": 15,
      "max": 30
    },
    {
      "id": "frequency",
      "label": "Target pitch frequency",
      "kind": "number",
      "hint": null,
      "default": 329.63,
      "unit": "Hz",
      "min": 40,
      "max": 1000
    }
  ],
  "outputs": [
    {
      "id": "tension",
      "label": "String tension",
      "format": "decimal",
      "hint": null,
      "primary": true
    },
    {
      "id": "unitWeightUsed",
      "label": "Unit weight used (lb/in)",
      "format": "decimal",
      "hint": null,
      "primary": false
    }
  ],
  "worked_example": {
    "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"
    ],
    "outputs": [
      "String tension: 16.31",
      "Unit weight used (lb/in): 0.00002"
    ]
  },
  "how_to": {
    "title": "How to use this",
    "steps": [
      "Enter string gauge (in (thousandths, e.g. 0.010)).",
      "Enter unit weight override (lb/in, 0 = auto plain steel estimate).",
      "Enter scale length (in).",
      "Enter target pitch frequency (Hz).",
      "Read your string tension on the right — it updates as you type.",
      "Hit Share to keep the scenario or send it to someone."
    ]
  },
  "scenarios": [
    {
      "name": "Conservative",
      "description": "Lower-end numbers — what if things land soft?",
      "values": {
        "gauge": 0.007,
        "unitWeight": 0,
        "scaleLength": 15.299999999999999,
        "frequency": 197.778
      }
    },
    {
      "name": "Typical",
      "description": "Defaults — the most common real-world setup.",
      "values": {
        "gauge": 0.01,
        "unitWeight": 0,
        "scaleLength": 25.5,
        "frequency": 329.63
      }
    },
    {
      "name": "Ambitious",
      "description": "Higher-end numbers — what if things really pop?",
      "values": {
        "gauge": 0.016,
        "unitWeight": 0,
        "scaleLength": 30,
        "frequency": 527.408
      }
    }
  ],
  "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."
  ],
  "faq": [
    {
      "q": "Why does scale length matter so much for tension?",
      "a": "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."
    },
    {
      "q": "What's a comfortable total tension across a set?",
      "a": "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."
    },
    {
      "q": "Why does the calculator need a unit weight override for wound strings?",
      "a": "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."
    }
  ],
  "related": [
    "https://www.revenuelab.fyi/toolbox/tempo-bar-duration",
    "https://www.revenuelab.fyi/toolbox/room-mode-frequency"
  ],
  "license": "CC-BY-4.0",
  "citation": "RevenueLab — Guitar String Tension Calculator (https://www.revenuelab.fyi/toolbox/guitar-string-gauge-tension)"
}