curl --request POST \
  --url https://api.iotools.cloud/v1/tool/slope-grade-calculator \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "rise": "4",
  "run": "48",
  "unit": "in"
}
'

{
  "tool": "slope-grade-calculator",
  "tool_version": "1.0.2",
  "outputs": {
    "status": "A rise of 4 in over a run of 48 in is a 1 : 12 slope — 8.33% grade, 4.76° from horizontal.",
    "result": [
      {
        "property": "Slope Ratio",
        "value": "1 : 12"
      },
      {
        "property": "Grade (%)",
        "value": "8.33%"
      },
      {
        "property": "Angle",
        "value": "4.76°"
      },
      {
        "property": "Slope Length",
        "value": "48.17 in"
      }
    ],
    "reference": [
      {
        "standard": "ADA accessible ramp (max)",
        "grade": "8.33",
        "your-slope": "Same"
      },
      {
        "standard": "Recommended wheelchair ramp",
        "grade": "6.25",
        "your-slope": "2.08% steeper"
      },
      {
        "standard": "Typical driveway (max)",
        "grade": "12",
        "your-slope": "3.67% gentler"
      },
      {
        "standard": "Highway (max grade)",
        "grade": "6",
        "your-slope": "2.33% steeper"
      },
      {
        "standard": "Low-slope roof (min for drainage)",
        "grade": "16.7",
        "your-slope": "8.37% gentler"
      }
    ]
  },
  "credits_used": 5,
  "credits_remaining": null
}