Unit Conversion

Convert between units of measurement and discover available conversion types. Supports length, weight, volume, temperature, area, and speed conversions.

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Overview

Use Cases

Scientific and engineering calculations
Travel and distance planning
Recipe scaling and cooking conversions
Fitness and health tracking
Educational tools
Build unit selection dropdowns in UIs

Features

Length, weight, volume, temperature, area, and speed conversions

39 supported units across 6 categories

Human-readable formula in every response

Results rounded to 6 decimal places

Fast, no-database lookups

Endpoint to discover all available units

API Endpoints

Convert Units

Convert a value from one unit to another

GET

https://requiems.xyz/v1/technology/convert

Parameters

Name	Type	Required	Description
from	`string`	Required	Source unit key (e.g. miles, kg, c)
to	`string`	Required	Target unit key (e.g. km, lb, f)
value	`number`	Required	Numeric value to convert

Try it out

Live Demo

Request

from * (string)

Source unit key (e.g. miles, kg, c)

to * (string)

Target unit key (e.g. km, lb, f)

value * (number)

Numeric value to convert

Response Fields

Field	Type	Description
from	`string`	Source unit key
to	`string`	Target unit key
input	`number`	The original input value
result	`number`	The converted value (rounded to 6 decimal places)
formula	`string`	Human-readable conversion formula

Code Examples

curl "https://requiems.xyz/v1/technology/convert?from=miles&to=km&value=10" \
  -H "requiems-api-key: YOUR_API_KEY"

import requests

url = "https://requiems.xyz/v1/technology/convert"
params = {"from": "miles", "to": "km", "value": 10}
headers = {"requiems-api-key": "YOUR_API_KEY"}

response = requests.get(url, params=params, headers=headers)
print(response.json())

const params = new URLSearchParams({ from: 'miles', to: 'km', value: 10 });
const response = await fetch(`https://requiems.xyz/v1/technology/convert?${params}`, {
  headers: {
    'requiems-api-key': 'YOUR_API_KEY'
  }
});

const { data } = await response.json();
console.log(data.result); // 16.09344

require 'net/http'
require 'json'

uri = URI('https://requiems.xyz/v1/technology/convert')
uri.query = URI.encode_www_form(from: 'miles', to: 'km', value: 10)
request = Net::HTTP::Get.new(uri)
request['requiems-api-key'] = 'YOUR_API_KEY'

response = Net::HTTP.start(uri.hostname, uri.port, use_ssl: true) do |http|
  http.request(request)
end

data = JSON.parse(response.body)['data']
puts data['result'] # 16.09344

List Available Units

Returns all available unit conversion types grouped by measurement category

GET

https://requiems.xyz/v1/technology/convert/units

Try it out

Live Demo

Request

Response Fields

Field	Type	Description
length	`array<string>`	Available length units: millimeter (mm), centimeter (cm), meter (m), kilometer (km), inch (in), foot (ft), yard (yd), mile (miles), nautical mile (nmi)
weight	`array<string>`	Available weight units: milligram (mg), gram (g), kilogram (kg), metric ton (t), ounce (oz), pound (lb), stone (stone)
volume	`array<string>`	Available volume units: milliliter (ml), liter (l), teaspoon (tsp), tablespoon (tbsp), fluid ounce (fl_oz), cup (cup), pint (pt), quart (qt), gallon (gal)
temperature	`array<string>`	Available temperature units: celsius (c), fahrenheit (f), kelvin (k)
area	`array<string>`	Available area units: square millimeter (mm2), square centimeter (cm2), square meter (m2), square kilometer (km2), square inch (in2), square foot (ft2), square yard (yd2), acre (acre), hectare (ha)
speed	`array<string>`	Available speed units: meters per second (m_s), kilometers per hour (km_h), miles per hour (mph), knots (knots)

Code Examples

curl https://requiems.xyz/v1/technology/convert/units \
  -H "requiems-api-key: YOUR_API_KEY"

import requests

url = "https://requiems.xyz/v1/technology/convert/units"
headers = {"requiems-api-key": "YOUR_API_KEY"}

response = requests.get(url, headers=headers)
units = response.json()['data']

# Print all length units
print("Length units:", units['length'])

const response = await fetch('https://requiems.xyz/v1/technology/convert/units', {
  headers: {
    'requiems-api-key': 'YOUR_API_KEY'
  }
});

const { data } = await response.json();

// Build a dropdown with length units
data.length.forEach(unit => {
  console.log(`<option value="${unit}">${unit}</option>`);
});

require 'net/http'
require 'json'

uri = URI('https://requiems.xyz/v1/technology/convert/units')
request = Net::HTTP::Get.new(uri)
request['requiems-api-key'] = 'YOUR_API_KEY'

response = Net::HTTP.start(uri.hostname, uri.port, use_ssl: true) do |http|
  http.request(request)
end

units = JSON.parse(response.body)['data']
puts "Temperature units: #{units['temperature'].join(', ')}"

Batch Convert Units

convert up to 50 unit conversion operations in a single request.

POST

https://requiems.xyz/v1/technology/convert/batch

Parameters

Name	Type	Required	Description
operations	`array<object>`	Required	Array of operations to convert (min: 1, max: 50).

Try it out

Live Demo

Request

operations * (array<object>)

Array of operations to convert (min: 1, max: 50).

Response Fields

Field	Type	Description
results	`array<object>`	List of unit conversion results returned in the same order as the input operations.
results[].from	`string`	Source unit used for the conversion.
results[].to	`string`	Target unit used for the conversion.
results[].success	`boolean`	Indicates whether the conversion operation was successful.
results[].error	`string`	Error message if the conversion failed. Empty when success is true.
results[].data	`object`	Conversion result details. Contains empty values when the conversion fails.
results[].data.from	`string`	Source unit.
results[].data.to	`string`	Target unit.
results[].data.input	`number`	Original numeric value provided for conversion.
results[].data.result	`number`	Converted numeric result.
results[].data.formula	`string`	Formula or conversion factor used to calculate the result.
total	`integer`	Total number of conversion results returned.

Code Examples

curl -X POST "https://requiems.xyz/v1/technology/convert/batch" \
  -H "requiems-api-key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "operations": [
      {
        "from": "kg",
        "to": "lb",
        "value": 10
      },
      {
        "from": "c",
        "to": "f",
        "value": 5
      }
    ]
  }'

import requests

url = "https://requiems.xyz/v1/technology/convert/batch"

headers = {
  "requiems-api-key": "YOUR_API_KEY",
  "Content-Type": "application/json"
}

payload = {
  "operations": [
    {
      "from": "kg",
      "to": "lb",
      "value": 10
    },
    {
      "from": "c",
      "to": "f",
      "value": 5
    }
  ]
}

response = requests.post(url, headers=headers, json=payload)

for item in response.json()["data"]["results"]:
  print(item["from"], "->", item["to"])

  if item["success"]:
    print("Result:", item["data"]["result"])
    print("Formula:", item["data"]["formula"])
  else:
    print("Error:", item["error"])

const response = await fetch(
  'https://requiems.xyz/v1/technology/convert/batch',
  {
    method: 'POST',
    headers: {
      'requiems-api-key': 'YOUR_API_KEY',
      'Content-Type': 'application/json'
    },
    body: JSON.stringify({
      operations: [
        {
          from: 'kg',
          to: 'lb',
          value: 10
        },
        {
          from: 'c',
          to: 'f',
          value: 5
        }
      ]
    })
  }
);

const { data } = await response.json();

data.results.forEach(item => {
  console.log(item.from, '->', item.to);

  if (item.success) {
    console.log('Result:', item.data.result);
    console.log('Formula:', item.data.formula);
  } else {
    console.log('Error:', item.error);
  }
});

require 'net/http'
require 'json'

uri = URI('https://requiems.xyz/v1/technology/convert/batch')

request = Net::HTTP::Post.new(uri)

request['requiems-api-key'] = 'YOUR_API_KEY'
request['Content-Type'] = 'application/json'

request.body = {
  operations: [
    {
      from: 'kg',
      to: 'lb',
      value: 10
    },
    {
      from: 'c',
      to: 'f',
      value: 5
    }
  ]
}.to_json

response = Net::HTTP.start(uri.hostname, uri.port, use_ssl: true) do |http|
  http.request(request)
end

JSON.parse(response.body)['data']['results'].each do |item|
  puts "#{item['from']} -> #{item['to']}"

  if item['success']
    puts "Result: #{item['data']['result']}"
    puts "Formula: #{item['data']['formula']}"
  else
    puts "Error: #{item['error']}"
  end
end

Error Responses

validation_failed

The operations array is missing, empty, or contains more than 50 items.

bad_request

Invalid JSON, malformed request body, or unexpected field types.

No results found

No results found

Unit Conversion

Overview

Use Cases

Features

API Endpoints

Convert Units

Parameters

Try it out

Request

Response

Error

Response Fields

Code Examples

List Available Units

Try it out

Request

Response

Error

Response Fields

Code Examples

Batch Convert Units

Parameters

Try it out

Request

Response

Error

Response Fields

Code Examples

Error Responses

Frequently Asked Questions