{
  "slug": "tire-size",
  "title": "Tire Size Calculator",
  "heading": "Tire Size Calculator",
  "category": "other",
  "url": "https://www.revenuelab.fyi/toolbox/tire-size",
  "summary": "Outer diameter, sidewall height, and circumference from a tire code.",
  "description": "Convert a P-metric tire code (e.g. 225/65R17) into physical dimensions.",
  "formula": null,
  "dateModified": "2026-10-03",
  "run_url": "https://www.revenuelab.fyi/api/public/calc?tool=tire-size",
  "inputs": [
    {
      "id": "width",
      "label": "Section width",
      "kind": "number",
      "hint": null,
      "default": 225,
      "unit": "mm",
      "min": 0,
      "max": null
    },
    {
      "id": "ratio",
      "label": "Aspect ratio",
      "kind": "number",
      "hint": null,
      "default": 65,
      "unit": "%",
      "min": 0,
      "max": null
    },
    {
      "id": "rim",
      "label": "Rim diameter",
      "kind": "number",
      "hint": null,
      "default": 17,
      "unit": "in",
      "min": 0,
      "max": null
    }
  ],
  "outputs": [
    {
      "id": "diameter",
      "label": "Outer diameter",
      "format": "decimal",
      "hint": "inches",
      "primary": true
    },
    {
      "id": "sidewall",
      "label": "Sidewall height",
      "format": "decimal",
      "hint": "inches",
      "primary": false
    },
    {
      "id": "circumference",
      "label": "Circumference",
      "format": "decimal",
      "hint": "inches",
      "primary": false
    },
    {
      "id": "revsPerMile",
      "label": "Revolutions per mile",
      "format": "number",
      "hint": null,
      "primary": false
    }
  ],
  "worked_example": {
    "inputs": [
      "Section width: 225 mm",
      "Aspect ratio: 65 %",
      "Rim diameter: 17 in"
    ],
    "outputs": [
      "Outer diameter: 28.52",
      "Sidewall height: 5.76",
      "Circumference: 89.6",
      "Revolutions per mile: 707.26"
    ]
  },
  "how_to": {
    "title": "How to use this",
    "steps": [
      "Enter section width (mm).",
      "Enter aspect ratio (%).",
      "Enter rim diameter (in).",
      "Read your outer diameter 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": {
        "width": 135,
        "ratio": 39,
        "rim": 10.2
      }
    },
    {
      "name": "Typical",
      "description": "Defaults — the most common real-world setup.",
      "values": {
        "width": 225,
        "ratio": 65,
        "rim": 17
      }
    },
    {
      "name": "Ambitious",
      "description": "Higher-end numbers — what if things really pop?",
      "values": {
        "width": 360,
        "ratio": 104,
        "rim": 27.200000000000003
      }
    }
  ],
  "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": "How does the tire size calculator work?",
      "a": "Convert a P-metric tire code (e.g. 225/65R17) into physical dimensions."
    },
    {
      "q": "What do I need to enter?",
      "a": "3 values: section width, aspect ratio, and rim diameter. Each field starts with a sensible default, so you can change one number at a time and watch the result move."
    },
    {
      "q": "What does the outer diameter result mean?",
      "a": "inches 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."
    },
    {
      "q": "Is this calculator free, and do I need an account?",
      "a": "Yes, it's free, and no account is required. Nothing you type is stored on our servers — the maths runs entirely in your browser."
    },
    {
      "q": "How accurate is the result?",
      "a": "It applies the standard formula exactly, so the arithmetic is precise. Estimates assume standard, average conditions — local rules, pricing, and materials vary."
    },
    {
      "q": "Who is this tool for?",
      "a": "It's built for anyone doing everyday planning maths — a quick estimate that would otherwise need four browser tabs and a calculator app."
    }
  ],
  "related": [],
  "license": "CC-BY-4.0",
  "citation": "RevenueLab — Tire Size Calculator (https://www.revenuelab.fyi/toolbox/tire-size)"
}