curl --request POST \
  --url https://api.iotools.cloud/v1/tool/cable-conduit-fill-calculator \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "unit": "mm",
  "conduitDiameter": "21",
  "cables": "6.5:3\n9.2:2",
  "fillStandard": "nec",
  "customFillPercent": "40"
}
'

{
  "tool": "cable-conduit-fill-calculator",
  "tool_version": "1.0.1",
  "outputs": {
    "result": [
      {
        "metric": "Conduit Area",
        "value": "346.4 mm²"
      },
      {
        "metric": "Total Cable Count",
        "value": "5"
      },
      {
        "metric": "Total Cable Area",
        "value": "232.5 mm²"
      },
      {
        "metric": "Fill Percentage",
        "value": "67.13 %"
      },
      {
        "metric": "Allowed Fill Percentage",
        "value": "40 % (NEC (5 cables))"
      },
      {
        "metric": "Allowed Fill Area",
        "value": "138.5 mm²"
      },
      {
        "metric": "Status",
        "value": "Exceeds allowed fill by 94 mm²"
      },
      {
        "metric": "Room for More 9.2 mm Cables",
        "value": "0"
      }
    ],
    "breakdown": [
      {
        "diameter": "6.5 mm",
        "qty": "3",
        "group-area": "99.5 mm²",
        "of-conduit-area": "28.74 %"
      },
      {
        "diameter": "9.2 mm",
        "qty": "2",
        "group-area": "133 mm²",
        "of-conduit-area": "38.39 %"
      }
    ]
  },
  "credits_used": 3,
  "credits_remaining": null
}