{
"category": "shoe",
"group": "men",
"womenScale": "common",
"input": {
"size": "9",
"system": "us",
"read": 9,
"label": "US men's 9"
},
"footLength": {
"mm": 262.5,
"cm": 26.25,
"in": 10.33
},
"sizes": {
"us": {
"size": "9",
"value": 9,
"exact": 9,
"label": "US men's 9",
"range": {
"low": "8.5",
"high": "9.5"
}
},
"usWomen": {
"size": "10.5",
"value": 10.5,
"exact": 10.5,
"label": "US women's 10.5",
"range": {
"low": "10",
"high": "11"
}
},
"uk": {
"size": "8",
"value": 8,
"exact": 8,
"label": "UK 8",
"range": {
"low": "7.5",
"high": "8.5"
}
},
"eu": {
"size": "41.5",
"value": 41.5,
"exact": 41.37,
"label": "EU 41.5",
"range": {
"low": "41.5",
"high": "42.5"
}
},
"jp": {
"size": "26",
"value": 26,
"exact": 26.25,
"label": "JP 26 cm",
"range": {
"low": "25.5",
"high": "26.5"
}
},
"kr": {
"size": "260",
"value": 260,
"exact": 262.47,
"label": "KR 260",
"range": {
"low": "255",
"high": "265"
}
},
"cn": {
"size": "260",
"value": 260,
"exact": 262.47,
"label": "CN 260",
"range": {
"low": "255",
"high": "265"
}
},
"mondopoint": {
"size": "260",
"value": 260,
"exact": 262.47,
"label": "Mondopoint 260",
"range": {
"low": "255",
"high": "265"
}
}
},
"basis": {
"us": "US men's = 3 × foot length (in) − 22 (customary US scale, men's 1 = 25 barleycorns of last).",
"usWomen": "US women's = 3 × foot length (in) − 20.5 (the common scale: men's + 1.5).",
"uk": "UK adult = 3 × foot length (in) − 23 = 3/25.4 × L − 23 (barleycorn scale with a two-size last allowance).",
"eu": "EU (Paris point, 2/3 cm) = 3/20 × L + 2 = 1.5 × last length (cm), last = foot + 2 Paris points.",
"jp": "Japan (JIS S 5037): foot length in cm, 0.5 cm steps.",
"kr": "Korea (KS M 6681): foot length in mm, 5 mm steps.",
"cn": "China (GB/T 3293.1): foot length in mm, 5 mm steps (many Chinese shops also print EU numbers).",
"mondopoint": "Mondopoint (ISO 9407): foot length in mm; 5 mm steps for casual and sports shoes."
},
"notes": [],
"variance": {
"sizes": 0.5,
"note": "Expect about half a size either way between brands for the same foot. \"range\" shows the labels this foot could carry.",
"details": [
"Brands' EU labels often run 0.5-1 size above the standard formula for the same UK or US size (1.5 for children's shoes), so EU ranges reach up.",
"US women's sizes are usually men's + 1.5 (\"common\" scale); some makers use men's + 1 (\"fia\"). Set womenScale to match.",
"A brand's \"cm\" label is often the shoe's inside length, 0.5-1 cm more than the foot; JP/KR/CN/Mondopoint here are foot length.",
"Width (narrow, wide) and the shoe's style (boots, running, dress) change the fit more than the conversion does."
]
},
"disclaimer": "Sizes vary by brand, style and country of manufacture. These conversions come from public sizing formulas and body-measurement rules, not from any brand's chart: treat them as a starting point and check the brand's own size chart and measurements before buying, selling or listing."
}
curl --location --request GET 'https://zylalabs.com/api/14590/size+chart+converter+api/37388/convert+a+shoe+size?size=9&from=us&group=men&womenScale=common' --header 'Authorization: Bearer YOUR_API_KEY'
{
"category": "ring",
"input": {
"size": "7",
"system": "us",
"read": 7,
"label": "US 7"
},
"circumference": {
"mm": 54.41,
"in": 2.142
},
"diameter": {
"mm": 17.32,
"in": 0.682
},
"sizes": {
"us": {
"size": "7",
"value": 7,
"exact": 7,
"label": "US 7",
"range": {
"low": "6.75",
"high": "7.25"
}
},
"uk": {
"size": "N½",
"value": 13.5,
"exact": 13.53,
"label": "UK N½",
"range": {
"low": "N",
"high": "O"
}
},
"iso": {
"size": "54",
"value": 54,
"exact": 54.41,
"label": "ISO 54",
"range": {
"low": "54",
"high": "55"
}
},
"ch": {
"size": "14",
"value": 14,
"exact": 14.41,
"label": "CH/IT/ES 14",
"range": {
"low": "14",
"high": "15"
}
},
"jp": {
"size": "14",
"value": 14,
"exact": 14.41,
"label": "JP 14",
"range": {
"low": "14",
"high": "15"
}
},
"diameter": {
"size": "17.3",
"value": 17.3,
"exact": 17.32,
"label": "17.3 mm diameter",
"range": {
"low": "17.1",
"high": "17.5"
}
}
},
"basis": {
"us": "US/Canada/Mexico: inside diameter = 11.63 + 0.8128 × size mm (0.032 in per whole size); circumference = π × diameter.",
"uk": "UK/Ireland/Australia/NZ: letters A-Z then Z+1..., 1.25 mm of inside circumference per letter, C = 40 mm (BS 6820:1987), half letters at 0.625 mm.",
"iso": "ISO 8653 (France, Belgium, Nordic and most of continental Europe): the inside circumference in mm.",
"ch": "Switzerland, Italy, Spain: inside circumference in mm − 40.",
"jp": "Japan (also used loosely in China and Korea): about circumference − 40 mm, 1 mm per size. Approximate: no published linear rule; makers' tables differ by about one size.",
"diameter": "Inside diameter = circumference / π (Germany and the Netherlands label rings this way)."
},
"notes": [],
"variance": {
"sizes": 0.25,
"note": "Jewellers' sizers differ by about a quarter US size (half a UK letter). \"range\" shows the labels within that.",
"details": [
"Wide bands (6 mm or more) fit tighter: many people go up a quarter to half size.",
"Fingers are larger in the heat and late in the day; measure the finger more than once.",
"Japanese sizes are approximate (no published linear rule); makers' tables differ by about one size."
]
},
"disclaimer": "Sizes vary by brand, style and country of manufacture. These conversions come from public sizing formulas and body-measurement rules, not from any brand's chart: treat them as a starting point and check the brand's own size chart and measurements before buying, selling or listing."
}
curl --location --request GET 'https://zylalabs.com/api/14590/size+chart+converter+api/37389/convert+a+ring+size?size=7&from=us' --header 'Authorization: Bearer YOUR_API_KEY'
{
"category": "hat",
"input": {
"size": "7 1/8",
"system": "us",
"read": 7.125,
"label": "US 7 1/8"
},
"headCircumference": {
"cm": 56.9,
"in": 22.38
},
"sizes": {
"us": {
"size": "7 1/8",
"value": 7.125,
"exact": 7.13,
"label": "US 7 1/8",
"range": {
"low": "7",
"high": "7 1/4"
}
},
"uk": {
"size": "7",
"value": 7,
"exact": 7,
"label": "UK 7",
"range": {
"low": "6 7/8",
"high": "7 1/8"
}
},
"eu": {
"size": "57",
"value": 57,
"exact": 56.85,
"label": "57 cm",
"range": {
"low": "56",
"high": "58"
}
},
"in": {
"size": "22 3/8",
"value": 22.375,
"exact": 22.38,
"label": "22 3/8 in",
"range": {
"low": "22 1/8",
"high": "22 3/4"
}
},
"letter": {
"size": "M",
"value": 3,
"exact": 56.85,
"label": "M",
"band": {
"from": 56.5,
"to": 58.5,
"unit": "cm"
},
"range": {
"low": "S",
"high": "M"
}
}
},
"basis": {
"us": "US fitted hat size = head circumference (in) / π (the head's diameter in inches), in eighths; about circumference (cm) / 8.",
"uk": "UK fitted hat size = US size − 1/8.",
"eu": "Metric (EU) hat size = head circumference in whole cm.",
"in": "Head circumference in inches, to the nearest 1/8.",
"letter": "Our own 2 cm letter bands: S 55-56 cm, M 57-58, L 59-60, XL 61-62 (makers differ by up to a band; adjustable caps often span two)."
},
"notes": [
"Between two sizes, take the larger one (a hat band can be padded smaller, not stretched much larger)."
],
"variance": {
"sizes": 0.125,
"note": "One eighth (about 1 cm of head circumference) either way between makers. Letter sizes vary the most.",
"details": [
"Measure around the head about 1 cm above the ears and eyebrows.",
"Letter sizes (S, M, L) are our own 2 cm bands; makers' bands differ by up to one band and adjustable caps often cover two."
]
},
"disclaimer": "Sizes vary by brand, style and country of manufacture. These conversions come from public sizing formulas and body-measurement rules, not from any brand's chart: treat them as a starting point and check the brand's own size chart and measurements before buying, selling or listing."
}
curl --location --request GET 'https://zylalabs.com/api/14590/size+chart+converter+api/37390/convert+a+hat+size?size=7 1/8&from=us' --header 'Authorization: Bearer YOUR_API_KEY'
{
"category": "clothing",
"type": "women",
"input": {
"size": "8",
"system": "us",
"read": 8,
"label": "US 8"
},
"body": {
"bust": {
"cm": 91.4,
"in": 36
}
},
"sizes": {
"us": {
"size": "8",
"value": 8,
"exact": 8,
"label": "US 8",
"range": {
"low": "6",
"high": "10"
}
},
"uk": {
"size": "12",
"value": 12,
"exact": 12,
"label": "UK 12",
"range": {
"low": "10",
"high": "14"
}
},
"fr": {
"size": "42",
"value": 42,
"exact": 41.72,
"label": "FR 42",
"range": {
"low": "40",
"high": "44"
}
},
"de": {
"size": "40",
"value": 40,
"exact": 39.72,
"label": "DE 40",
"range": {
"low": "38",
"high": "42"
}
},
"it": {
"size": "46",
"value": 46,
"exact": 45.72,
"label": "IT 46",
"range": {
"low": "44",
"high": "48"
}
},
"jp": {
"size": "15",
"value": 15,
"exact": 14.63,
"label": "JP 15",
"range": {
"low": "11",
"high": "17"
}
},
"letter": {
"size": "M",
"value": 3,
"exact": 91.44,
"label": "M",
"band": {
"from": 90,
"to": 98,
"unit": "cm"
},
"range": {
"low": "S",
"high": "M"
}
}
},
"basis": {
"us": "US misses = bust (in) − 28 (US 8 = 36 in bust).",
"uk": "UK and Australia/NZ = bust (in) − 24 (UK 12 = 36 in bust).",
"fr": "France (also Belgium, Spain) = bust (cm) / 2 − 4.",
"de": "Germany (also Austria, Netherlands, Scandinavia) = bust (cm) / 2 − 6.",
"it": "Italy = bust (cm) / 2.",
"jp": "Japan JIS L 4005 odd sizes by bust: 3 = 74 cm, 3 cm per size up to 15 = 92 cm, then 4 cm per size.",
"letter": "Our own bust bands (cm) following the German size groups: XS = DE 32-34, S = 36-38, M = 40-42, L = 44-46, XL = 48-50, XXL = 52-54."
},
"notes": [],
"variance": {
"sizes": 1,
"note": "Expect one size either way between brands for the same body (vanity sizing). Compare the bust, waist and hip figures on the brand's chart.",
"details": [
"Many US and UK brands now cut a size or two larger than the measurement rule (vanity sizing), so retail charts often pair US 8 with FR 40 / DE 38 / IT 44 where the rule gives one size up; \"range\" includes both.",
"This converts by bust; for trousers and skirts the waist and hip decide, and they vary even more between brands.",
"Japanese sizes also carry body shape and height letters (Y, A, AB, B; PP, P, R, T) that this conversion ignores."
]
},
"disclaimer": "Sizes vary by brand, style and country of manufacture. These conversions come from public sizing formulas and body-measurement rules, not from any brand's chart: treat them as a starting point and check the brand's own size chart and measurements before buying, selling or listing."
}
curl --location --request GET 'https://zylalabs.com/api/14590/size+chart+converter+api/37391/convert+a+clothing+size?type=women&size=8&from=us' --header 'Authorization: Bearer YOUR_API_KEY'
{
"category": "ring",
"from": "us",
"count": 65,
"rows": [
{
"size": "0",
"label": "US 0",
"sizes": {
"us": "0",
"uk": null,
"iso": "37",
"ch": null,
"jp": null,
"diameter": "11.6"
},
"circumferenceMm": 36.54
},
{
"size": "0.25",
"label": "US 0.25",
"sizes": {
"us": "0.25",
"uk": null,
"iso": "37",
"ch": null,
"jp": null,
"diameter": "11.8"
},
"circumferenceMm": 37.18
},
{
"size": "0.5",
"label": "US 0.5",
"sizes": {
"us": "0.5",
"uk": "A½",
"iso": "38",
"ch": null,
"jp": null,
"diameter": "12"
},
"circumferenceMm": 37.81
},
{
"size": "0.75",
"label": "US 0.75",
"sizes": {
"us": "0.75",
"uk": "B",
"iso": "38",
"ch": null,
"jp": null,
"diameter": "12.2"
},
"circumferenceMm": 38.45
},
{
"size": "1",
"label": "US 1",
"sizes": {
"us": "1",
"uk": "B½",
"iso": "39",
"ch": null,
"jp": null,
"diameter": "12.4"
},
"circumferenceMm": 39.09
}
],
"basis": {
"us": "US/Canada/Mexico: inside diameter = 11.63 + 0.8128 × size mm (0.032 in per whole size); circumference = π × diameter.",
"uk": "UK/Ireland/Australia/NZ: letters A-Z then Z+1..., 1.25 mm of inside circumference per letter, C = 40 mm (BS 6820:1987), half letters at 0.625 mm.",
"iso": "ISO 8653 (France, Belgium, Nordic and most of continental Europe): the inside circumference in mm.",
"ch": "Switzerland, Italy, Spain: inside circumference in mm − 40.",
"jp": "Japan (also used loosely in China and Korea): about circumference − 40 mm, 1 mm per size. Approximate: no published linear rule; makers' tables differ by about one size.",
"diameter": "Inside diameter = circumference / π (Germany and the Netherlands label rings this way)."
},
"notes": [
"Each row is the nearest label in every system; see the single-size endpoints for exact values and ranges."
],
"variance": {
"sizes": 0.25,
"note": "Jewellers' sizers differ by about a quarter US size (half a UK letter). \"range\" shows the labels within that.",
"details": [
"Wide bands (6 mm or more) fit tighter: many people go up a quarter to half size.",
"Fingers are larger in the heat and late in the day; measure the finger more than once.",
"Japanese sizes are approximate (no published linear rule); makers' tables differ by about one size."
]
},
"disclaimer": "Sizes vary by brand, style and country of manufacture. These conversions come from public sizing formulas and body-measurement rules, not from any brand's chart: treat them as a starting point and check the brand's own size chart and measurements before buying, selling or listing."
}
curl --location --request GET 'https://zylalabs.com/api/14590/size+chart+converter+api/37392/a+whole+compiled+chart?category=ring&from=us' --header 'Authorization: Bearer YOUR_API_KEY'
{
"categories": {
"shoe": {
"endpoint": "/shoe",
"measure": "foot length (mm)",
"groups": [
"men",
"women",
"kids"
],
"from": [
"us",
"us-men",
"us-women",
"uk",
"eu",
"jp",
"kr",
"cn",
"mondopoint",
"foot-cm",
"foot-in"
],
"womenScale": [
"common",
"fia"
],
"answers": [
"us",
"usMen or usWomen",
"uk",
"eu",
"jp",
"kr",
"cn",
"mondopoint"
],
"kidsSizes": "US and UK kids sizes 1-6.5 need a scale mark: C (children's, e.g. \"2C\") or Y (big kids/youth, e.g. \"2Y\"); 0-0.5 and 7-13.5 are read as children's."
},
"ring": {
"endpoint": "/ring",
"measure": "inside circumference (mm)",
"from": [
"us",
"uk",
"iso",
"eu",
"ch",
"jp",
"diameter",
"circumference"
],
"aliases": {
"ca": "us",
"mx": "us",
"au": "uk",
"ie": "uk",
"nz": "uk",
"za": "uk",
"fr": "iso",
"it": "ch",
"es": "ch",
"cn": "jp",
"kr": "jp"
},
"answers": [
"us",
"uk",
"iso",
"ch",
"jp",
"diameter"
]
},
"hat": {
"endpoint": "/hat",
"measure": "head circumference (cm)",
"from": [
"us",
"uk",
"eu",
"cm",
"in",
"letter"
],
"answers": [
"us",
"uk",
"eu",
"in",
"letter"
]
},
"clothing": {
"endpoint": "/clothing",
"types": {
"women": {
"measure": "bust (cm)",
"from": [
"us",
"uk",
"fr",
"de",
"it",
"jp",
"letter",
"bust-cm",
"bust-in"
],
"aliases": {
"au": "uk",
"nz": "uk",
"eu": "fr",
"es": "fr",
"be": "fr",
"at": "de",
"nl": "de"
},
"answers": [
"us",
"uk",
"fr",
"de",
"it",
"jp",
"letter"
]
},
"men-suits": {
"measure": "chest (cm)",
"from": [
"us",
"eu",
"letter",
"chest-cm",
"chest-in"
],
"aliases": {
"uk": "us",
"de": "eu",
"fr": "eu",
"it": "eu"
},
"answers": [
"us",
"eu",
"letter"
]
},
"men-shirts": {
"measure": "neck (cm)",
"from": [
"us",
"eu",
"letter",
"neck-cm",
"neck-in"
],
"aliases": {
"uk": "us",
"jp": "eu"
},
"answers": [
"us",
"eu",
"letter"
]
}
}
}
},
"disclaimer": "Sizes vary by brand, style and country of manufacture. These conversions come from public sizing formulas and body-measurement rules, not from any brand's chart: treat them as a starting point and check the brand's own size chart and measurements before buying, selling or listing."
}
curl --location --request GET 'https://zylalabs.com/api/14590/size+chart+converter+api/37393/supported+categories+systems+and+aliases' --header 'Authorization: Bearer YOUR_API_KEY'
After signing up, every developer is assigned a personal API access key, a unique combination of letters and digits provided to access to our API endpoint. To authenticate with the Size Chart Converter API simply include your bearer token in the Authorization header.
| Header | Description |
|---|---|
Authorization
|
Required
Should be Bearer access_key. See "Your API Access Key" above when you are subscribed.
|
No long-term commitment. Upgrade, downgrade, or cancel anytime.
Shoe, ring, hat and clothing sizes between US, UK, EU and Japan, with brand-variance ranges.
Each endpoint returns size conversion data for shoes, rings, hats, and clothing, including measurements in various units (mm, cm, in) and size labels across different systems (US, UK, EU, Japan).
Key fields include "category" (type of item), "input" (user's size and system), "sizes" (converted sizes in various systems), and "range" (size variance). Each field provides essential information for size conversions.
Parameters include "size" (the original size), "system" (the size system used), and for some endpoints, "type" (e.g., women, men). Users can specify these to customize their conversion requests.
The response is structured with a main category, input details, and a sizes object containing converted sizes for various systems. Each size entry includes the size, value, label, and range for clarity.
The data is derived from established sizing standards and formulas, such as ISO for rings and common sizing practices for clothing and footwear. This ensures consistency and reliability across conversions.
Typical use cases include e-commerce platforms needing size conversions for international customers, fashion retailers providing size guides, and applications helping users find their correct sizes across brands.
Users can utilize the returned data by referencing the "sizes" object to find equivalent sizes in different systems, ensuring accurate fit when purchasing items from various regions or brands.
Data accuracy is maintained through adherence to sizing standards and regular updates based on industry practices. The API also accounts for brand-variance ranges to reflect real-world sizing discrepancies.
To obtain your API key, first sign in to your account and navigate to the API you want to use. From the API's Pricing section, choose a plan and complete the subscription process. Once subscribed, return to the API page and you will see your API Access Key displayed at the top of the documentation page. You can use this key to authenticate your requests.
You can’t switch APIs during the free trial. If you subscribe to a different API, your trial will end and the new subscription will start as a paid plan.
The free trial lasts for 7 days and allows you to make up to 50 API requests.
No, the free trial is available only once, so we recommend using it on the API that interests you the most. Most of our APIs offer a free trial, but some may not include this option.
Yes. If the API offers a free trial, you will see a "Free 7-Day Trial" option in its Pricing section. The trial lasts for 7 days and allows up to 50 API requests, enabling you to evaluate the API before subscribing to a paid plan.
Zyla API Hub is like a big store for APIs, where you can find thousands of them all in one place. We also offer dedicated support and real-time monitoring of all APIs. Once you sign up, you can pick and choose which APIs you want to use. Just remember, each API needs its own subscription. But if you subscribe to multiple ones, you'll use the same key for all of them, making things easier for you.
You can monitor your API usage through the response headers included with every request:
x-zyla-api-calls-monthly-used: Shows the total number of API requests you have used during the current billing period.
x-zyla-api-calls-monthly-remaining: Shows the number of API requests you have remaining for the current billing period.
Yes, you can cancel your subscription at any time. Simply go to the Pricing section of the API you're subscribed to and click the "Unsubscribe" button.
Please note that upgrades, downgrades, and cancellations take effect immediately. Once your subscription is canceled, access to the service will end immediately, regardless of any remaining API calls in your quota.
Please have a look at our Refund Policy: https://zylalabs.com/terms#refund