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RingSizeConvert.com

Universal Ring Size Converter

Convert ring sizes instantly across US, UK, EU, Germany, and Japan sizing systems with exact millimeter measurements.

Need other tools?Ring size calculator (finger measurement) →|International ring size chart →
How would you like to find your size?

Numeric size (e.g. 8) for US/Canada, EU, or Japan — or a letter size (e.g. P 1/2) for UK/Australia.

Prefer a live slider?

Drag to your inner diameter measurement — results update instantly, no button needed.

Measure straight across the inside of a ring, or your finger's wrapped circumference converted to diameter.

Save sizes for people you shop for

Keep a private list of sizes — yours or people you buy for. Saved only on this device, never uploaded or synced.

Saved sizes

No sizes saved yet on this device.

Saved sizes stay only in this browser's local storage — no account, no server, nothing uploaded. Clearing your browser data (or using a different browser/device) will remove them. See our privacy policy for details.

Ring size conversion chart preview

Quick reference for common sizes across every supported sizing system.

Common ring sizes at a glance
US / CanadaUS, CA, MXUK / AustraliaUK, IE, AU, NZ, ZAEUEU, FR, AT, BE, DK, SE, NO, FIGermany / NetherlandsDE, NLTurkeyTRJapanJP, CN, KR, HK, SGIndia (BlueStone)INIndia (Jewelove)India (VowJewels)India (The Vedic Crystals)Diameter (mm)Circumference (mm)
US / CanadaUS, CA, MX4UK / AustraliaUK, IE, AU, NZ, ZAHEUEU, FR, AT, BE, DK, SE, NO, FI47Germany / NetherlandsDE, NL15TurkeyTR6.75JapanJP, CN, KR, HK, SG7India (BlueStone)IN6.75India (Jewelove)6.75India (VowJewels)6India (The Vedic Crystals)7Diameter (mm)14.88Circumference (mm)46.75
US / CanadaUS, CA, MX5UK / AustraliaUK, IE, AU, NZ, ZAJ½EUEU, FR, AT, BE, DK, SE, NO, FI49.5Germany / NetherlandsDE, NL15.5TurkeyTR9.32JapanJP, CN, KR, HK, SG9India (BlueStone)IN9.32India (Jewelove)9.32India (VowJewels)8India (The Vedic Crystals)9Diameter (mm)15.7Circumference (mm)49.32
US / CanadaUS, CA, MX6UK / AustraliaUK, IE, AU, NZ, ZAL½EUEU, FR, AT, BE, DK, SE, NO, FI52Germany / NetherlandsDE, NL16.5TurkeyTR11.87JapanJP, CN, KR, HK, SG11India (BlueStone)IN11.87India (Jewelove)11.87India (VowJewels)10India (The Vedic Crystals)11Diameter (mm)16.51Circumference (mm)51.87
US / CanadaUS, CA, MX7UK / AustraliaUK, IE, AU, NZ, ZAN½EUEU, FR, AT, BE, DK, SE, NO, FI54.5Germany / NetherlandsDE, NL17.5TurkeyTR14.41JapanJP, CN, KR, HK, SG14India (BlueStone)IN14.41India (Jewelove)14.41India (VowJewels)12India (The Vedic Crystals)13Diameter (mm)17.32Circumference (mm)54.41
US / CanadaUS, CA, MX8UK / AustraliaUK, IE, AU, NZ, ZAP½EUEU, FR, AT, BE, DK, SE, NO, FI57Germany / NetherlandsDE, NL18TurkeyTR16.99JapanJP, CN, KR, HK, SG16India (BlueStone)IN16.99India (Jewelove)16.99India (VowJewels)14India (The Vedic Crystals)15Diameter (mm)18.14Circumference (mm)56.99
US / CanadaUS, CA, MX9UK / AustraliaUK, IE, AU, NZ, ZAR½EUEU, FR, AT, BE, DK, SE, NO, FI59.5Germany / NetherlandsDE, NL19TurkeyTR19.53JapanJP, CN, KR, HK, SG18India (BlueStone)IN19.53India (Jewelove)19.53India (VowJewels)16India (The Vedic Crystals)17Diameter (mm)18.95Circumference (mm)59.53
US / CanadaUS, CA, MX10UK / AustraliaUK, IE, AU, NZ, ZAT½EUEU, FR, AT, BE, DK, SE, NO, FI62Germany / NetherlandsDE, NL20TurkeyTR22.08JapanJP, CN, KR, HK, SG20India (BlueStone)IN22.08India (Jewelove)22.08India (VowJewels)18India (The Vedic Crystals)19Diameter (mm)19.76Circumference (mm)62.08
US / CanadaUS, CA, MX11UK / AustraliaUK, IE, AU, NZ, ZAV½EUEU, FR, AT, BE, DK, SE, NO, FI64.5Germany / NetherlandsDE, NL20.5TurkeyTR24.62JapanJP, CN, KR, HK, SG23India (BlueStone)IN24.62India (Jewelove)24.62India (VowJewels)20India (The Vedic Crystals)21Diameter (mm)20.57Circumference (mm)64.62
US / CanadaUS, CA, MX12UK / AustraliaUK, IE, AU, NZ, ZAX½EUEU, FR, AT, BE, DK, SE, NO, FI67Germany / NetherlandsDE, NL21.5TurkeyTR27.2JapanJP, CN, KR, HK, SG25India (BlueStone)IN27.2India (Jewelove)27.2India (VowJewels)22India (The Vedic Crystals)23Diameter (mm)21.39Circumference (mm)67.2

Lower-confidence data — Japan, India (VowJewels), India (The Vedic Crystals) comes from a single published retailer source, or is known to drift by 1–2 sizes at the top of the range. Confirm with the retailer before ordering.

Rounded scale — Germany / Netherlands uses a coarser step than US half-sizes, so one value can cover two neighbouring US sizes. Check the millimeter columns when you need to tell them apart.

View the full ring size chart →

How to measure your ring size

Diagram of a ring showing the inside diameter being measured
Measure the inside edge of the ring, not the outside — the inner diameter is what determines your size.

Read the complete ring size measuring guide →

Frequently asked questions

How accurate is this online ring size converter?

Conversions are mathematically aligned with standard international sizing systems (US/Canada, UK/Australia, EU, Germany, and Japan) anchored to millimeter inner diameter and circumference measurements. However, because fit can vary by band width and manufacturer tolerances, always confirm with the specific jeweler before purchasing.

Which international ring sizing systems can I convert between?

The converter supports US/Canada numeric sizes, UK/Australia letter sizes, EU (ISO 8653) circumference sizes in millimeters, German diameter sizes, Japanese numeric sizes, and popular Indian jewelry brand conventions.

What should I do if my converted size falls between two sizes?

When your size falls between standard increments, we recommend choosing the larger size for wide bands (6 mm or wider) and the smaller size for narrow, delicate bands. You can also test both options in our dedicated ring size calculator.

Does band width change my ring size conversion?

Yes. Wider bands (6 mm or wider) contact more surface area of the finger and create more friction when sliding over the knuckle, so jewelers frequently recommend ordering a half-size larger than your standard thin-band size.

How do I convert a ring size from a physical measurement?

If you have an inside diameter measurement from an existing ring or a circumference measurement from wrapping paper around your finger, enter it directly into the calculator to convert your raw millimeters into any standard international ring size.

Where can I see the complete international ring size chart?

You can view our complete international ring size chart for the full side-by-side reference matrix comparing all adult sizes from US 3 to 13.5 across all global systems.