{
  "title": "Crown molding angle calculator",
  "human_url": "https://happytails.ai/en/calculators/crown-molding-angle-calculator/",
  "agent_url": "https://happytails.ai/agents/en/calculators/crown-molding-angle-calculator/",
  "language": "en",
  "markdown_url": "https://happytails.ai/en/calculators/crown-molding-angle-calculator.md",
  "content": "Crown molding angle calculator\nGet the miter and bevel settings for crown molding laid flat on a compound miter saw, and the miter for a nested cut, from the corner angle and the spring angle. Each piece gets its fence edge, miter and bevel direction and the side to keep.\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 Crown molding angle calculator\nChoose an inside or outside corner and enter the angle between the two walls.\nEnter the spring angle and say whether it is measured from the wall or the ceiling.\nRead the flat miter and bevel, the nested miter and the setup for the left and right pieces.\nMake a test cut on scrap, then download the JSON report or the setup CSV.\nUseful next steps\nAngle\nCut list optimizer\nLumber board foot calculator\nAngle conventions\nCorner angle W is the angle between the two wall surfaces on the side where it is under 180 degrees: 90 for any square corner, inside or outside. Spring angle S is the angle between the wall and the back of the molding, from the edge touching the wall to the edge touching the ceiling: 38 for 52/38 crown, 45 for 45/45 crown. If your molding gives the angle from the ceiling, choose that option and it is converted to 90 − S.\nFlat compound cuts\nWith the molding face up and its back on the table, miter = arctan(sin S ÷ tan(W ÷ 2)) and bevel = arcsin(cos S × cos(W ÷ 2)) (Wikipedia, Crown molding, Angle calculations, checked 16 October 2026). For a square corner and 38 degree spring this gives the familiar 31.62 degree miter and 33.86 degree bevel. We checked both formulas and every left, right, inside and outside setup against an independent three-dimensional vector derivation using right-triangle trigonometry (OpenStax Precalculus 2e, 5.4, checked 16 October 2026).\nSaw directions\nThe miter is read from 0 for a square cut, and Right means the front of the blade swings to your right as you face the saw. The bevel is the blade tilt from vertical, and Left means the top of the blade tilts left, as on most single-bevel saws. If your saw tilts right, put the other edge of the molding on the fence and keep the piece on the other side of the blade, with the same miter.\nNested cuts and limits\nNested, the molding stands upside down with its ceiling edge on the table and its wall edge on the fence at its spring angle; then the miter is 90° − W ÷ 2 with no bevel. Left and right pieces are as seen facing the corner. Real spring angles and corners often differ from nominal, so cut scrap first, and expect warnings when a setting passes 50 degrees of miter or 45 of bevel.",
  "content_format": "text/plain",
  "visibility": "public",
  "links": [
    {
      "name": "Angle",
      "url": "https://happytails.ai/en/unit-converters/angle/"
    },
    {
      "name": "Cut list optimizer",
      "url": "https://happytails.ai/en/calculators/cut-list-optimizer/"
    },
    {
      "name": "Lumber board foot calculator",
      "url": "https://happytails.ai/en/calculators/lumber-board-foot-calculator/"
    }
  ],
  "tool": {
    "id": "crown-molding-angle-calculator",
    "category": "calculators",
    "built": true,
    "requirements": "Corner angles from 10 to 179 degrees and spring angles from 1 to 89 degrees, measured from the wall or the ceiling. Angles are rounded to 0.01 degree. Calculated on your device; download a JSON report, a results CSV and a saw setup CSV.",
    "implementation": {
      "fields": [
        {
          "key": "cornerType",
          "label": "Corner",
          "value": "Inside corner",
          "type": "select",
          "values": [
            "Inside corner",
            "Outside corner"
          ]
        },
        {
          "key": "wallAngle",
          "label": "Corner angle between the walls (degrees)",
          "value": 90,
          "type": "number",
          "min": 10,
          "max": 179,
          "step": "any",
          "help": "Angle between the two wall surfaces on the side where it is under 180 degrees: 90 for a square corner, inside or outside, and 135 at a 45 degree bay."
        },
        {
          "key": "springReference",
          "label": "Spring angle measured from",
          "value": "The wall",
          "type": "select",
          "values": [
            "The wall",
            "The ceiling"
          ]
        },
        {
          "key": "springAngle",
          "label": "Spring angle (degrees)",
          "value": 38,
          "type": "number",
          "min": 1,
          "max": 89,
          "step": "any",
          "help": "Angle between the molding back (wall edge to ceiling edge) and the reference surface. 52/38 crown is 38 from the wall or 52 from the ceiling; 45/45 crown is 45."
        }
      ],
      "registrationFamily": "roof-and-cladding",
      "input": false,
      "live": true,
      "presentation": "metrics",
      "note": "Calculated on your device for corner angles from 10 to 179 degrees and spring angles from 1 to 89 degrees. Miter is read from a square cut; bevel is the blade tilt from vertical.",
      "experience": {
        "automatic": true,
        "single": true,
        "inputMaxLength": 1000000,
        "inputMode": "text",
        "label": "Corner and molding angles",
        "placeholder": "Use the fields below",
        "help": "This calculator uses the measurement fields only. Results update as you type. Up to 1,000,000 characters.",
        "action": null
      },
      "mode": "automatic",
      "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": "# Crown molding angle calculator\n\n- Human page: https://happytails.ai/en/calculators/crown-molding-angle-calculator/\n- Markdown: https://happytails.ai/en/calculators/crown-molding-angle-calculator.md\n- Structured JSON: https://happytails.ai/agents/en/calculators/crown-molding-angle-calculator/index.json\n- Visibility: public\n\n## Tool capabilities\n\n| Property | Value |\n| --- | --- |\n| Tool ID | `crown-molding-angle-calculator` |\n| Category | calculators |\n| Implementation | Registered implementation. Registration alone is not a production-quality guarantee. |\n| Browser execution | Automatic updates after valid input or file selection. |\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\nCalculated on your device for corner angles from 10 to 179 degrees and spring angles from 1 to 89 degrees. Miter is read from a square cut; bevel is the blade tilt from vertical.\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| `cornerType` | Corner | select | \"Inside corner\" | Allowed: Inside corner, Outside corner |\n| `wallAngle` | Corner angle between the walls (degrees) | number | 90 | min=10 max=179 step=any |\n| `springReference` | Spring angle measured from | select | \"The wall\" | Allowed: The wall, The ceiling |\n| `springAngle` | Spring angle (degrees) | number | 38 | min=1 max=89 step=any |\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\nCorner angles from 10 to 179 degrees and spring angles from 1 to 89 degrees, measured from the wall or the ceiling. Angles are rounded to 0.01 degree. Calculated on your device; download a JSON report, a results CSV and a saw setup CSV.\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\": \"crown-molding-angle-calculator\",\n  \"category\": \"calculators\",\n  \"built\": true,\n  \"requirements\": \"Corner angles from 10 to 179 degrees and spring angles from 1 to 89 degrees, measured from the wall or the ceiling. Angles are rounded to 0.01 degree. Calculated on your device; download a JSON report, a results CSV and a saw setup CSV.\",\n  \"implementation\": {\n    \"fields\": [\n      {\n        \"key\": \"cornerType\",\n        \"label\": \"Corner\",\n        \"value\": \"Inside corner\",\n        \"type\": \"select\",\n        \"values\": [\n          \"Inside corner\",\n          \"Outside corner\"\n        ]\n      },\n      {\n        \"key\": \"wallAngle\",\n        \"label\": \"Corner angle between the walls (degrees)\",\n        \"value\": 90,\n        \"type\": \"number\",\n        \"min\": 10,\n        \"max\": 179,\n        \"step\": \"any\",\n        \"help\": \"Angle between the two wall surfaces on the side where it is under 180 degrees: 90 for a square corner, inside or outside, and 135 at a 45 degree bay.\"\n      },\n      {\n        \"key\": \"springReference\",\n        \"label\": \"Spring angle measured from\",\n        \"value\": \"The wall\",\n        \"type\": \"select\",\n        \"values\": [\n          \"The wall\",\n          \"The ceiling\"\n        ]\n      },\n      {\n        \"key\": \"springAngle\",\n        \"label\": \"Spring angle (degrees)\",\n        \"value\": 38,\n        \"type\": \"number\",\n        \"min\": 1,\n        \"max\": 89,\n        \"step\": \"any\",\n        \"help\": \"Angle between the molding back (wall edge to ceiling edge) and the reference surface. 52/38 crown is 38 from the wall or 52 from the ceiling; 45/45 crown is 45.\"\n      }\n    ],\n    \"registrationFamily\": \"roof-and-cladding\",\n    \"input\": false,\n    \"live\": true,\n    \"presentation\": \"metrics\",\n    \"note\": \"Calculated on your device for corner angles from 10 to 179 degrees and spring angles from 1 to 89 degrees. Miter is read from a square cut; bevel is the blade tilt from vertical.\",\n    \"experience\": {\n      \"automatic\": true,\n      \"single\": true,\n      \"inputMaxLength\": 1000000,\n      \"inputMode\": \"text\",\n      \"label\": \"Corner and molding angles\",\n      \"placeholder\": \"Use the fields below\",\n      \"help\": \"This calculator uses the measurement fields only. Results update as you type. Up to 1,000,000 characters.\",\n      \"action\": null\n    },\n    \"mode\": \"automatic\",\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\nGet the miter and bevel settings for crown molding laid flat on a compound miter saw, and the miter for a nested cut, from the corner angle and the spring angle. Each piece gets its fence edge, miter and bevel direction and the side to keep.\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 Crown molding angle calculator\n\n1. Choose an inside or outside corner and enter the angle between the two walls.\n2. Enter the spring angle and say whether it is measured from the wall or the ceiling.\n3. Read the flat miter and bevel, the nested miter and the setup for the left and right pieces.\n4. Make a test cut on scrap, then download the JSON report or the setup CSV.\n\n## Useful next steps\n\n- [Angle](https://happytails.ai/en/unit-converters/angle/) ([Markdown](https://happytails.ai/en/unit-converters/angle.md))\n\n- [Cut list optimizer](https://happytails.ai/en/calculators/cut-list-optimizer/) ([Markdown](https://happytails.ai/en/calculators/cut-list-optimizer.md))\n\n- [Lumber board foot calculator](https://happytails.ai/en/calculators/lumber-board-foot-calculator/) ([Markdown](https://happytails.ai/en/calculators/lumber-board-foot-calculator.md))\n\n## Angle conventions\n\nCorner angle W is the angle between the two wall surfaces on the side where it is under 180 degrees: 90 for any square corner, inside or outside. Spring angle S is the angle between the wall and the back of the molding, from the edge touching the wall to the edge touching the ceiling: 38 for 52/38 crown, 45 for 45/45 crown. If your molding gives the angle from the ceiling, choose that option and it is converted to 90 − S.\n\n### Flat compound cuts\n\nWith the molding face up and its back on the table, miter = arctan(sin S ÷ tan(W ÷ 2)) and bevel = arcsin(cos S × cos(W ÷ 2)) (Wikipedia, Crown molding, Angle calculations, checked 16 October 2026). For a square corner and 38 degree spring this gives the familiar 31.62 degree miter and 33.86 degree bevel. We checked both formulas and every left, right, inside and outside setup against an independent three-dimensional vector derivation using right-triangle trigonometry (OpenStax Precalculus 2e, 5.4, checked 16 October 2026).\n\n### Saw directions\n\nThe miter is read from 0 for a square cut, and Right means the front of the blade swings to your right as you face the saw. The bevel is the blade tilt from vertical, and Left means the top of the blade tilts left, as on most single-bevel saws. If your saw tilts right, put the other edge of the molding on the fence and keep the piece on the other side of the blade, with the same miter.\n\n### Nested cuts and limits\n\nNested, the molding stands upside down with its ceiling edge on the table and its wall edge on the fence at its spring angle; then the miter is 90° − W ÷ 2 with no bevel. Left and right pieces are as seen facing the corner. Real spring angles and corners often differ from nominal, so cut scrap first, and expect warnings when a setting passes 50 degrees of miter or 45 of bevel.\n"
}