Overview
Unit Converter works by using formulas to convert units from one to another. Using a well defined set of units, it returns the converted value to the desired unit.
Endpoint
One host, one path per API. The block below shows this call in four languages; every one of them is the same HTTP request. Making requests covers the timeouts, retries and parameter rules that apply to all of them. The SDKs wrap the same call in a typed client.
curl "https://api.apiverve.com/v1/unitconverter?value=100&from=lb&to=kg" \
-H "x-api-key: your_api_key_here"const res = await fetch('https://api.apiverve.com/v1/unitconverter?value=100&from=lb&to=kg', {
headers: { 'x-api-key': 'your_api_key_here' },
});
if (!res.ok) throw new Error(`${res.status} ${await res.text()}`);
const { data } = await res.json();
console.log(data);import requests
res = requests.get(
"https://api.apiverve.com/v1/unitconverter?value=100&from=lb&to=kg",
headers={"x-api-key": "your_api_key_here"},
timeout=15,
)
res.raise_for_status()
print(res.json()["data"])package main
import (
"fmt"
"io"
"net/http"
)
func main() {
req, _ := http.NewRequest("GET", "https://api.apiverve.com/v1/unitconverter?value=100&from=lb&to=kg", nil)
req.Header.Set("x-api-key", "your_api_key_here")
res, err := http.DefaultClient.Do(req)
if err != nil {
panic(err)
}
defer res.Body.Close()
out, _ := io.ReadAll(res.Body)
fmt.Println(string(out))
}Replace your_api_key_here with the key from your dashboard. When the inputs arrive as a list rather than one at a time, batch requests run up to 200 of them through this same API in a single call.
Authentication
Send your key in the x-api-key header. That is the only auth step — there is no token exchange and no per-endpoint scope to configure. Authentication covers creating, rotating and revoking keys.
A 401 means the key is missing, invalid or expired. A 403 means the key is valid but not permitted here — blocked by a key restriction or an IP allow-list. Running out of credits is a 429.
Parameters
Sent in the query string. Premium parameters are accepted on every plan but only take effect on plans that include them.
| Parameter | Type | Description |
|---|---|---|
valueRequired | number | The value to convert |
fromRequired | string | The unit to convert from |
toRequired | string | The unit to convert to |
Response
Every API returns the same three top-level keys, so one response handler covers your whole integration: status, error and data. Only data changes shape. Response format covers the envelope, the other output formats and how premium fields are withheld.
{
"status": "ok",
"error": null,
"data": {
"result": {
"result": 45.36,
"from": "100 lb",
"to": "kg"
},
"unitDefinitions": {
"from": {
"abbr": "lb",
"measure": "mass",
"system": "imperial",
"singular": "Pound",
"plural": "Pounds"
},
"to": {
"abbr": "kg",
"measure": "mass",
"system": "metric",
"singular": "Kilogram",
"plural": "Kilograms"
}
}
}
}Response fields
Paths are relative to data. Premium fields are absent rather than zeroed on plans that do not include them, so check for presence instead of comparing to 0.
| Field | Type | Example | Description |
|---|---|---|---|
result | object | {...} | |
result | number | 45.36 | Converted numeric value in target units |
from | string | "100 lb" | Original value with source unit abbreviation |
to | string | "kg" | Target unit abbreviation for conversion |
unitDefinitions | object | {...} | |
from | object | {...} | |
abbrPremium | string | "lb" | Source unit abbreviation code |
measurePremium | string | "mass" | Physical quantity being measured from |
systemPremium | string | "imperial" | Measurement system of source unit |
singularPremium | string | "Pound" | Singular name of source unit |
pluralPremium | string | "Pounds" | Plural name of source unit |
to | object | {...} | |
abbrPremium | string | "kg" | Target unit abbreviation code |
measurePremium | string | "mass" | Physical quantity being measured to |
systemPremium | string | "metric" | Measurement system of target unit |
singularPremium | string | "Kilogram" | Singular name of target unit |
pluralPremium | string | "Kilograms" | Plural name of target unit |
Errors
Read the HTTP status first, then error for the specific reason. The body names the parameter that has to change. Error handling covers the full status list and which of them are worth retrying.
| Status | Meaning | What to do |
|---|---|---|
400 | Input was rejected | Read error; it names the parameter. |
401 | Key missing or invalid | Check the header name and the key value. |
403 | Key valid, but not permitted | A key restriction or IP allow-list; see key scoping. |
429 | Rate limited, or out of credits | Read error to tell them apart; see rate limits. |
Use cases
- Measurement Converters
- Convert measurements such as weight, length, area, temperature, and more by using the Unit Converter API. Use the API to convert units between different systems
- Unit Standardization
- Standardize units across different systems by using the Unit Converter API. Convert units to a common standard for consistency and compatibility
- Unit Calculation
- Perform unit calculations by using the Unit Converter API to convert units in mathematical operations. Use the API to simplify unit conversions in calculations
Other ways to use Unit Converter
Set up Unit Converter on APIVerve, or reach the same source a different way. Your APIVerve account and credits work on all of them — one key, one balance.
Related
More in Data Conversion: