OpenTools
Unit Converter

Unit Converter API

Utilities

Convert measurements instantly with natural language. Convert length, weight, temperature, volume, area, speed, time, and pressure without complex formulas.

Authentication

All API requests require a valid API key passed in the Authorization header as a Bearer token.

Rate Limit

50 requests per minute

Endpoints

1 endpoint available

Overview

The Unit Converter API converts between units of measurement using natural language queries. Simply describe what you want to convert in plain English and receive accurate conversions with detailed explanations.

Supported Conversions

  • Length - Kilometers, miles, meters, feet, inches, centimeters, etc.
  • Weight/Mass - Kilograms, pounds, ounces, grams, stones, etc.
  • Temperature - Celsius, Fahrenheit, Kelvin
  • Volume - Liters, gallons, quarts, cups, milliliters, etc.
  • Area - Square meters, square feet, acres, hectares, etc.
  • Speed - km/h, mph, m/s, knots, etc.
  • Time - Hours, minutes, seconds, days, weeks, etc.
  • Pressure - PSI, bar, Pascal, atmospheres, etc.
  • Data - Bytes, KB, MB, GB, TB, etc.

Use Cases

  • Engineering and scientific calculations
  • International e-commerce applications
  • Recipe and cooking apps
  • Travel and navigation applications
  • Educational tools and calculators

Endpoints

POST
/v1/tools/unit-converter
Convert units using natural language

Request Body

Content-Type: application/json

ParameterTypeRequiredDescription
query
string
Required
The conversion query in plain English (e.g., "Convert 5 kilometers to miles")

Response Example

{
  "success": true,
  "result": "3.11 miles",
  "explanation": "5 kilometers = 3.11 miles\\n\\nConversion factor: 1 kilometer = 0.621371 miles\\nCalculation: 5 × 0.621371 = 3.11 miles"
}

Error Codes

400
Invalid request body or empty query
401
Missing or invalid API key
422
Unable to parse the conversion query
429
Rate limit exceeded
500
Internal server error

Code Examples

curl -X POST https://api.opentools.ca/v1/tools/unit-converter \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"query": "Convert 5 kilometers to miles"}'

Ready to get started?

Create an API key to start using the Unit Converter API.