{
  "title": "Wheel offset calculator",
  "human_url": "https://happytails.ai/en/calculators/wheel-offset-calculator/",
  "agent_url": "https://happytails.ai/agents/en/calculators/wheel-offset-calculator/",
  "language": "en",
  "markdown_url": "https://happytails.ai/en/calculators/wheel-offset-calculator.md",
  "content": "Wheel offset calculator\nCompare nominal inner intrusion, outer protrusion and inner-clearance changes between two wheel widths and offsets.\nHow can we improve this tool?\nReport a problem or share an idea.\nPlease leave out private information. Your message and the tool name go to our team via PostHog.\nHow to use Wheel offset calculator\nEnter the current wheel nominal width in inches and signed offset in millimetres.\nEnter the proposed width and offset using the same mounting-plane assumption.\nReview the signed inner and outer changes, then download the full comparison.\nUseful next steps\nTire size comparison calculator\nGear ratio speed calculator\nUnderstand the signs\nNominal inner extent is half the width in mm plus offset; outer extent is half the width minus offset. Each reported change is proposed minus current. Positive inner intrusion reduces inner clearance, while positive outer protrusion moves outward.\nKeep the comparison geometric\nAn inch is exactly 25.4 mm. Nominal wheel width is measured between bead seats, not across the outside flanges. This model excludes tire bulge, flange geometry, spacers, brake clearance and suspension motion. It does not establish fitment, safety, approval or legality.",
  "content_format": "text/plain",
  "visibility": "public",
  "links": [
    {
      "name": "Tire size comparison calculator",
      "url": "https://happytails.ai/en/calculators/tire-size-comparison-calculator/"
    },
    {
      "name": "Gear ratio speed calculator",
      "url": "https://happytails.ai/en/calculators/gear-ratio-speed-calculator/"
    }
  ],
  "tool": {
    "id": "wheel-offset-calculator",
    "category": "calculators",
    "built": true,
    "requirements": "Widths are nominal bead-seat widths from 0.1 to 40 inches. Signed offsets are -500 to +500 mm. Positive offset places the mounting face outboard of the centerline. Positive inner intrusion reduces inner clearance; positive outer protrusion moves outward. Both wheels use the same mounting plane. Tire bulge, flange widths, spacers, brakes and suspension motion are excluded. These nominal position changes do not establish fitment, safety, vehicle approval or legality. Processing stays on your device in a cancellable worker with a 10-second timeout. Maximum 500000 combined input characters and 2000 records, with 30 tariffs or grades, 30 tiers per tariff and 100 depreciation years. Guided decimals allow up to six places without thousands separators. Full JSON and JSON Pointer CSV include all source inputs, units, assumptions and results; each file is capped at 2000000 characters and CSV at 200000 leaf records. All tariff totals precede the first 200 detail rows in the parking preview; other tables preview 200 rows. Software bounds are not vehicle capability claims. Results use floating-point arithmetic.",
    "implementation": {
      "fields": [
        {
          "key": "referenceWidthIn",
          "label": "Current wheel nominal width (in)",
          "value": "7",
          "type": "text",
          "inputMode": "decimal",
          "maxLength": 24,
          "help": "Use a decimal point, up to six decimal places and no thousands separators."
        },
        {
          "key": "referenceOffsetMm",
          "label": "Current wheel offset (mm)",
          "value": "45",
          "type": "text",
          "inputMode": "decimal",
          "maxLength": 24,
          "help": "Use a decimal point, up to six decimal places and no thousands separators."
        },
        {
          "key": "proposedWidthIn",
          "label": "Proposed wheel nominal width (in)",
          "value": "8",
          "type": "text",
          "inputMode": "decimal",
          "maxLength": 24,
          "help": "Use a decimal point, up to six decimal places and no thousands separators."
        },
        {
          "key": "proposedOffsetMm",
          "label": "Proposed wheel offset (mm)",
          "value": "35",
          "type": "text",
          "inputMode": "decimal",
          "maxLength": 24,
          "help": "Use a decimal point, up to six decimal places and no thousands separators."
        }
      ],
      "input": false,
      "presentation": "metrics",
      "note": "Widths are nominal bead-seat widths from 0.1 to 40 inches. Signed offsets are -500 to +500 mm. Positive offset places the mounting face outboard of the centerline. Positive inner intrusion reduces inner clearance; positive outer protrusion moves outward. Both wheels use the same mounting plane. Tire bulge, flange widths, spacers, brakes and suspension motion are excluded. These nominal position changes do not establish fitment, safety, vehicle approval or legality. Runs locally without uploads. Limit: 500000 combined input characters, 2000 records, 30 tariffs or grades, 30 tiers per tariff and 100 depreciation years. Complete JSON and JSON Pointer CSV exports are each capped at 2000000 characters and CSV at 200000 leaf records. Preview shows 200 report rows. Calculations stop after 10 seconds. Copy result copies the report text; downloads include source inputs, units, assumptions and complete results.",
      "inputMaxLength": 500000,
      "inputErrorCode": "VEHICLE_INPUT",
      "example": {
        "input": "",
        "options": {
          "referenceWidthIn": "7",
          "referenceOffsetMm": "45",
          "proposedWidthIn": "8",
          "proposedOffsetMm": "35"
        }
      },
      "experience": {
        "automatic": false,
        "single": false,
        "inputMaxLength": 500000,
        "inputMode": "text",
        "label": "Your text",
        "placeholder": "Type or paste your input…",
        "help": "Up to 500,000 characters. Review the settings before running.",
        "action": null
      },
      "mode": "explicit",
      "interactive": false
    },
    "execution": "Browser interface",
    "api": null,
    "browser_agent": {
      "supported": true,
      "name": "run_current_tool",
      "discovery": "WebMCP on the human page in a supporting browser",
      "verification": "See audit/API-AUDIT.md; availability is not verification"
    }
  },
  "markdown": "# Wheel offset calculator\n\n- Human page: https://happytails.ai/en/calculators/wheel-offset-calculator/\n- Markdown: https://happytails.ai/en/calculators/wheel-offset-calculator.md\n- Structured JSON: https://happytails.ai/agents/en/calculators/wheel-offset-calculator/index.json\n- Visibility: public\n\n## Tool capabilities\n\n| Property | Value |\n| --- | --- |\n| Tool ID | `wheel-offset-calculator` |\n| Category | calculators |\n| Implementation | Registered implementation. Registration alone is not a production-quality guarantee. |\n| Browser execution | Use the visible action or interactive controls. |\n| Browser processing | Browser; see tool notes for network behavior. |\n| HTTP API | Not callable through HTTP. |\n| Browser-agent interface | run_current_tool |\n\n### Implementation notes\n\nWidths are nominal bead-seat widths from 0.1 to 40 inches. Signed offsets are -500 to +500 mm. Positive offset places the mounting face outboard of the centerline. Positive inner intrusion reduces inner clearance; positive outer protrusion moves outward. Both wheels use the same mounting plane. Tire bulge, flange widths, spacers, brakes and suspension motion are excluded. These nominal position changes do not establish fitment, safety, vehicle approval or legality. Runs locally without uploads. Limit: 500000 combined input characters, 2000 records, 30 tariffs or grades, 30 tiers per tariff and 100 depreciation years. Complete JSON and JSON Pointer CSV exports are each capped at 2000000 characters and CSV at 200000 leaf records. Preview shows 200 report rows. Calculations stop after 10 seconds. Copy result copies the report text; downloads include source inputs, units, assumptions and complete results.\n\n### Inputs and settings\n\nNo free-text input is required. Use the file inputs and/or settings below.\n\n| Setting | Meaning | Control type | Default | Constraints |\n| --- | --- | --- | --- | --- |\n| `referenceWidthIn` | Current wheel nominal width (in) | text | \"7\" |  |\n| `referenceOffsetMm` | Current wheel offset (mm) | text | \"45\" |  |\n| `proposedWidthIn` | Proposed wheel nominal width (in) | text | \"8\" |  |\n| `proposedOffsetMm` | Proposed wheel offset (mm) | text | \"35\" |  |\n\n### Browser-agent workflow\n\n1. Open the human page in a browser that supports WebMCP.\n2. Discover the interface exposed by that page; use its actual schema.\n3. Select files on the page first when the tool requires files.\n4. Call `run_current_tool` with valid input and settings.\n5. Inspect the returned result or error and the displayed output. Retrieve files from the displayed download links.\n\nCalls do not automatically copy or download results. Browser permissions still apply. Interface availability alone is not proof of successful execution.\n\n### Planning specification\n\nWidths are nominal bead-seat widths from 0.1 to 40 inches. Signed offsets are -500 to +500 mm. Positive offset places the mounting face outboard of the centerline. Positive inner intrusion reduces inner clearance; positive outer protrusion moves outward. Both wheels use the same mounting plane. Tire bulge, flange widths, spacers, brakes and suspension motion are excluded. These nominal position changes do not establish fitment, safety, vehicle approval or legality. Processing stays on your device in a cancellable worker with a 10-second timeout. Maximum 500000 combined input characters and 2000 records, with 30 tariffs or grades, 30 tiers per tariff and 100 depreciation years. Guided decimals allow up to six places without thousands separators. Full JSON and JSON Pointer CSV include all source inputs, units, assumptions and results; each file is capped at 2000000 characters and CSV at 200000 leaf records. All tariff totals precede the first 200 detail rows in the parking preview; other tables preview 200 rows. Software bounds are not vehicle capability claims. Results use floating-point arithmetic.\n\nThis describes intended requirements. Use the implementation notes, interface schema and observed output to determine current support.\n\n### Complete machine-readable capability record\n\n```json\n{\n  \"id\": \"wheel-offset-calculator\",\n  \"category\": \"calculators\",\n  \"built\": true,\n  \"requirements\": \"Widths are nominal bead-seat widths from 0.1 to 40 inches. Signed offsets are -500 to +500 mm. Positive offset places the mounting face outboard of the centerline. Positive inner intrusion reduces inner clearance; positive outer protrusion moves outward. Both wheels use the same mounting plane. Tire bulge, flange widths, spacers, brakes and suspension motion are excluded. These nominal position changes do not establish fitment, safety, vehicle approval or legality. Processing stays on your device in a cancellable worker with a 10-second timeout. Maximum 500000 combined input characters and 2000 records, with 30 tariffs or grades, 30 tiers per tariff and 100 depreciation years. Guided decimals allow up to six places without thousands separators. Full JSON and JSON Pointer CSV include all source inputs, units, assumptions and results; each file is capped at 2000000 characters and CSV at 200000 leaf records. All tariff totals precede the first 200 detail rows in the parking preview; other tables preview 200 rows. Software bounds are not vehicle capability claims. Results use floating-point arithmetic.\",\n  \"implementation\": {\n    \"fields\": [\n      {\n        \"key\": \"referenceWidthIn\",\n        \"label\": \"Current wheel nominal width (in)\",\n        \"value\": \"7\",\n        \"type\": \"text\",\n        \"inputMode\": \"decimal\",\n        \"maxLength\": 24,\n        \"help\": \"Use a decimal point, up to six decimal places and no thousands separators.\"\n      },\n      {\n        \"key\": \"referenceOffsetMm\",\n        \"label\": \"Current wheel offset (mm)\",\n        \"value\": \"45\",\n        \"type\": \"text\",\n        \"inputMode\": \"decimal\",\n        \"maxLength\": 24,\n        \"help\": \"Use a decimal point, up to six decimal places and no thousands separators.\"\n      },\n      {\n        \"key\": \"proposedWidthIn\",\n        \"label\": \"Proposed wheel nominal width (in)\",\n        \"value\": \"8\",\n        \"type\": \"text\",\n        \"inputMode\": \"decimal\",\n        \"maxLength\": 24,\n        \"help\": \"Use a decimal point, up to six decimal places and no thousands separators.\"\n      },\n      {\n        \"key\": \"proposedOffsetMm\",\n        \"label\": \"Proposed wheel offset (mm)\",\n        \"value\": \"35\",\n        \"type\": \"text\",\n        \"inputMode\": \"decimal\",\n        \"maxLength\": 24,\n        \"help\": \"Use a decimal point, up to six decimal places and no thousands separators.\"\n      }\n    ],\n    \"input\": false,\n    \"presentation\": \"metrics\",\n    \"note\": \"Widths are nominal bead-seat widths from 0.1 to 40 inches. Signed offsets are -500 to +500 mm. Positive offset places the mounting face outboard of the centerline. Positive inner intrusion reduces inner clearance; positive outer protrusion moves outward. Both wheels use the same mounting plane. Tire bulge, flange widths, spacers, brakes and suspension motion are excluded. These nominal position changes do not establish fitment, safety, vehicle approval or legality. Runs locally without uploads. Limit: 500000 combined input characters, 2000 records, 30 tariffs or grades, 30 tiers per tariff and 100 depreciation years. Complete JSON and JSON Pointer CSV exports are each capped at 2000000 characters and CSV at 200000 leaf records. Preview shows 200 report rows. Calculations stop after 10 seconds. Copy result copies the report text; downloads include source inputs, units, assumptions and complete results.\",\n    \"inputMaxLength\": 500000,\n    \"inputErrorCode\": \"VEHICLE_INPUT\",\n    \"example\": {\n      \"input\": \"\",\n      \"options\": {\n        \"referenceWidthIn\": \"7\",\n        \"referenceOffsetMm\": \"45\",\n        \"proposedWidthIn\": \"8\",\n        \"proposedOffsetMm\": \"35\"\n      }\n    },\n    \"experience\": {\n      \"automatic\": false,\n      \"single\": false,\n      \"inputMaxLength\": 500000,\n      \"inputMode\": \"text\",\n      \"label\": \"Your text\",\n      \"placeholder\": \"Type or paste your input…\",\n      \"help\": \"Up to 500,000 characters. Review the settings before running.\",\n      \"action\": null\n    },\n    \"mode\": \"explicit\",\n    \"interactive\": false\n  },\n  \"execution\": \"Browser interface\",\n  \"api\": null,\n  \"browser_agent\": {\n    \"supported\": true,\n    \"name\": \"run_current_tool\",\n    \"discovery\": \"WebMCP on the human page in a supporting browser\",\n    \"verification\": \"See audit/API-AUDIT.md; availability is not verification\"\n  }\n}\n```\n\n## Page guide\n\nCompare nominal inner intrusion, outer protrusion and inner-clearance changes between two wheel widths and offsets.\n\nHow can we improve this tool?\n\nReport a problem or share an idea.\n\nPlease leave out private information. Your message and the tool name go to our team via PostHog.\n\n### How to use Wheel offset calculator\n\n1. Enter the current wheel nominal width in inches and signed offset in millimetres.\n2. Enter the proposed width and offset using the same mounting-plane assumption.\n3. Review the signed inner and outer changes, then download the full comparison.\n\n## Useful next steps\n\n- [Tire size comparison calculator](https://happytails.ai/en/calculators/tire-size-comparison-calculator/) ([Markdown](https://happytails.ai/en/calculators/tire-size-comparison-calculator.md))\n\n- [Gear ratio speed calculator](https://happytails.ai/en/calculators/gear-ratio-speed-calculator/) ([Markdown](https://happytails.ai/en/calculators/gear-ratio-speed-calculator.md))\n\n## Understand the signs\n\nNominal inner extent is half the width in mm plus offset; outer extent is half the width minus offset. Each reported change is proposed minus current. Positive inner intrusion reduces inner clearance, while positive outer protrusion moves outward.\n\n### Keep the comparison geometric\n\nAn inch is exactly 25.4 mm. Nominal wheel width is measured between bead seats, not across the outside flanges. This model excludes tire bulge, flange geometry, spacers, brake clearance and suspension motion. It does not establish fitment, safety, approval or legality.\n"
}