curl --request POST \
  --url https://api.iotools.cloud/v1/tool/gear-ratio-calculator \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "mode": "single",
  "driverTeeth": "20",
  "drivenTeeth": "60",
  "train": "20, 60\n15, 45",
  "inputSpeed": "1750",
  "inputTorque": "50",
  "efficiency": "100"
}
'

{
  "tool": "gear-ratio-calculator",
  "tool_version": "1.0.1",
  "outputs": {
    "results": [
      {
        "quantity": "Total gear ratio",
        "value": "3"
      },
      {
        "quantity": "Ratio notation",
        "value": "3 : 1"
      },
      {
        "quantity": "Drive type",
        "value": "Reduction — output turns slower with more torque"
      },
      {
        "quantity": "Stages",
        "value": "1"
      },
      {
        "quantity": "Mechanical advantage",
        "value": "3×"
      },
      {
        "quantity": "Output speed",
        "value": "583.333 rpm"
      },
      {
        "quantity": "Speed change",
        "value": "-66.6667 %"
      },
      {
        "quantity": "Output torque (ideal)",
        "value": "150 N·m"
      }
    ],
    "stageTable": [
      {
        "stage": "1",
        "driver-driven": "20 → 60",
        "stage-ratio": "3 : 1",
        "speed-out-rpm": "583.333",
        "torque-out-n-m": "150"
      }
    ],
    "breakdown": "Stage ratio = driven teeth ÷ driver teeth\nTotal ratio = 60/20 = 3\nOutput speed = 1750 rpm ÷ 3 = 583.333 rpm\nOutput torque = 50 N·m × 3 = 150 N·m\nIdeal calculation — drop the efficiency below 100% to account for mesh losses."
  },
  "credits_used": 3,
  "credits_remaining": null
}