X percent of Y

Compute X percent of Y — the basic percentage portion calculation used for discounts, taxes, tips, and commission math.

Formula

result = (X ÷ 100) × Y

Both inputs are real numbers. Example: 15% of 240 → (15 / 100) × 240 = 36.

When to use it

Quick sale-price reductions, VAT-exclusive back-calculations, tip estimates on a subtotal, or homework checks without spreadsheet setup.

Limitations

Floating-point rounding may show long decimal tails; format results for currency according to your locale’s minor units. Negative percentages model decreases but interpret business meaning carefully. Does not compound multiple successive percentages automatically.

Example

15% of 200 equals 30 because (15 ÷ 100) × 200 = 30. A 8% sales tax on a 49.99 subtotal is about 4.00 before rounding to currency minor units. A 20% tip on 85 is 17. Negative percentages model decreases; interpret the business meaning carefully for discounts versus fees.

This skill is available over A2A JSON-RPC and REST. When you already know the skill id and export, call execute directly—no discovery step required.

REST example

curl -sS -X POST https://toolplaza.app/api/helpers/execute \
  -H 'Content-Type: application/json' \
  -d '{"skillId":"percentage-calculator__x-percent-of-y","export":"xPercentOfY","args":["Hello"]}'

A2A JSON-RPC example

Send POST https://toolplaza.app/api/a2a with:

{
  "jsonrpc": "2.0",
  "id": "1",
  "method": "message/send",
  "params": {
    "message": {
      "messageId": "uuid",
      "role": "user",
      "parts": [
        {
          "kind": "text",
          "text": "ignored"
        }
      ]
    },
    "metadata": {
      "toolplaza": {
        "skillId": "percentage-calculator__x-percent-of-y",
        "export": "xPercentOfY",
        "args": [
          "Hello"
        ]
      }
    }
  }
}

Full Agent API guide · Skill schema