Overview
Ring Size Converter works by converting input sizes to diameter measurements, then calculating equivalent sizes in all supported regions. Can accept either standardized sizes or direct diameter measurements for maximum flexibility.
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/ringsizeconverter?size=7&from=us" \
-H "x-api-key: your_api_key_here"const res = await fetch('https://api.apiverve.com/v1/ringsizeconverter?size=7&from=us', {
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/ringsizeconverter?size=7&from=us",
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/ringsizeconverter?size=7&from=us", 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 |
|---|---|---|
sizeRequired | string | The ring size to convert |
fromRequired | string | Source regionusukeujpchau |
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": {
"input_diameter_mm": 17.3,
"circumference_mm": 54.3,
"conversions": {
"diameter_mm": 17.3,
"circumference_mm": 54.3,
"us": 7,
"uk": "N",
"eu": 52,
"jp": 17,
"ch": -22,
"au": "N"
},
"note": "Sizes are approximate. For accurate sizing, visit a jeweler."
}
}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 |
|---|---|---|---|
input_diameter_mm | number | 17.3 | Ring diameter in millimeters |
circumference_mm | number | 54.3 | Inside circumference of the ring in millimetres |
conversions | object | {...} | The equivalent size in every supported sizing system |
diameter_mm | number | 17.3 | Inside diameter in millimetres |
circumference_mm | number | 54.3 | Inside circumference in millimetres |
us | number | 7 | US ring size |
uk | string | "N" | UK ring size |
euPremium | number | 52 | EU ring size |
jpPremium | number | 17 | Japanese ring size |
chPremium | number | -22 | Swiss ring size |
auPremium | string | "N" | Australian ring size |
note | string | "Sizes are approximate. For accurate sizing, visit a jeweler." | Caveat that sizes are approximate and a jeweller should confirm |
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
- Jewelry E-commerce
- Help customers find their ring size when purchasing from international jewelers and retailers
- Gift Shopping
- Convert ring sizes when buying jewelry gifts for people in different countries
- Jewelry Sizing
- Provide sizing tools for jewelers working with international customers and standards
- Size Guides
- Create comprehensive ring size conversion charts for jewelry product listings
Other ways to use Ring Size Converter
Set up Ring Size 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 Reference Data: