Percentage Calculator API
Calculate X% of a number, find what percent X is of Y, or compute percentage change — instantly.
Fast & Accurate
Get precise results instantly.
Easy Integration
Simple REST API with JSON response.
Developer Friendly
Clear docs and SDK examples.
Free to Start
1,000 free requests/month.
Endpoint
All requests should be made to the following endpoint:
GET https://api.tools.town/v1/calculators/percentage Authentication
This endpoint requires an API Key. Include your API key in the request header.
Request Parameters
Send a GET request with query parameters.
| Parameter | Type | Required | Description | Example |
|---|---|---|---|---|
mode | string | ✓ | Calculation mode: find, what-percent, or change. | find |
percent | number | ✓ | Percentage value. | 15 |
of | number | ✓ | Base number. | 2000 |
Example Request
curl -G "https://api.tools.town/v1/calculators/percentage" \
-H "Authorization: Bearer YOUR_API_KEY" \
--data-urlencode "mode=find" \
--data-urlencode "percent=15" \
--data-urlencode "of=2000" Error Codes
| Code | Meaning |
|---|---|
| 400 | Bad Request — missing or invalid parameter |
| 401 | Unauthorized — API key missing or invalid |
| 429 | Rate limit exceeded — free tier: 1,000 requests/month |
| 500 | Internal Server Error — try again or contact support |