US Ring & Dress Size Converter
EverydayConvert US ring sizes to EU, UK, Japan, and India standards. Convert US dress sizes to UK, EU, Australian, Italian, and Japanese equivalents. Free lookup table.
US 7 equals…
| US/CA | EU/ISO | UK | Japan | India | Dia. (mm) |
|---|---|---|---|---|---|
| 7 | 54.5 | N | 14 | 14 | 17.3 |
Full Ring Size Chart
| US/CA | EU/ISO | UK | Japan | India | Dia. (mm) |
|---|---|---|---|---|---|
| 3 | 44 | F | 4 | — | 14.1 |
| 3.5 | 45.5 | G | 6 | — | 14.5 |
| 4 | 47 | H | 7 | — | 14.9 |
| 4.5 | 48 | I | 8 | — | 15.3 |
| 5 | 49 | J | 9 | 9 | 15.7 |
| 5.5 | 50.5 | K | 10 | 10 | 16.1 |
| 6 | 52 | L | 12 | 12 | 16.5 |
| 6.5 | 53.5 | M | 13 | 13 | 16.9 |
| 7 | 54.5 | N | 14 | 14 | 17.3 |
| 7.5 | 56 | O | 15 | 15 | 17.7 |
| 8 | 57 | P | 16 | 16 | 18.1 |
| 8.5 | 58.5 | Q | 17 | 17 | 18.5 |
| 9 | 59.5 | R | 18 | 18 | 18.9 |
| 9.5 | 61 | S | 19 | 19 | 19.4 |
| 10 | 62 | T | 20 | 20 | 19.8 |
| 10.5 | 63.5 | U | 21 | 21 | 20.2 |
| 11 | 65 | V | 22 | 22 | 20.6 |
| 11.5 | 66 | W | 23 | 23 | 21 |
| 12 | 67 | X | 24 | 24 | 21.4 |
| 12.5 | 68.5 | Y | 25 | 25 | 21.8 |
| 13 | 70 | Z | 26 | 26 | 22.2 |
What is a Ring & Dress Size?
The US Ring & Dress Size Converter is a free lookup tool that translates US and Canadian clothing and jewellery sizes into every major international standard — covering six ring size systems and six dress size systems simultaneously. Whether you are shopping from a UK retailer, ordering jewellery from a Japanese brand, or buying a saree blouse from an Indian boutique and need a size reference, this converter gives you an accurate equivalent in seconds.
Ring sizes vary dramatically across countries. The US / Canada system uses an abstract numeric scale, while the EU / ISO system expresses size in millimetres of inner circumference, the UK / Ireland / AU / NZ system uses a letter-plus-half-step scale, Japan and East Asia use yet another numeric scale, and India uses a scale that resembles UK numbering with its own offsets. Switching between these without a reference table is error-prone and can result in an ill-fitting ring — a costly mistake with fine jewellery.
Dress sizes are equally fragmented. A US size 8 means something different to a UK retailer, an Italian fashion house, a Japanese brand, and an Indian apparel manufacturer — all four will label the same garment with a different number. Relying on memory or guesswork when shopping internationally almost guarantees sizing errors.
This converter covers both sizing domains in one place. For ring sizes, it uses the inner diameter in millimetres as the universal intermediate unit, ensuring mathematically precise conversions across all six systems. For dress sizes, it maps equivalent sizes using the industry-standard offset tables used by international fashion buyers. You can also use the Clothing Size Converter for women's tops and bottoms between India, US, UK, and EU, and the Shoe Size Converter to complete your full outfit sizing reference.
How to use this Ring & Dress Size calculator
- Select your source unit — open the "From" dropdown and choose the size system you already know. For ring conversions, pick from the Ring Size group (e.g., "US / Canada Ring Size"). For dress conversions, pick from the Dress Size group (e.g., "US / Canada Dress Size").
- Select your target unit — open the "To" dropdown and choose the system you want to convert into. Make sure both From and To units are from the same group (both Ring Size, or both Dress Size).
- Enter your current size — type your size into the input field. For ring sizes this is a number (e.g., 7 or 7.5). For dress sizes this is a whole number (e.g., 8 or 12).
- Read the converted result — the equivalent size in your target system appears immediately below the input. For ring conversions via "Inner Diameter (mm)", the result will be a decimal value in millimetres.
- Swap directions — use the swap ⇅ button between the two dropdowns to reverse the conversion instantly. This is useful when you know the target system's size and want to verify what it maps back to.
- Interpret the result — for ring sizes, if the converted value falls between two sizes in the target system, choose the larger size for a comfortable fit. For dress sizes, use the result as a starting point and consult the brand's size chart to confirm, since cut and fabric affect fit independently of the size label.
Formula & Methodology
### Ring Size Conversions All ring size conversions use inner diameter in millimetres as the universal base unit. Every size in every system maps to a diameter value, and conversion is a two-step lookup: 1. Convert source size → inner diameter (mm) 2. Convert inner diameter (mm) → target size US size to inner diameter formula:Diameter (mm) = 11.63 + (US Size × 0.8128)EU / ISO size to inner diameter: EU size represents inner circumference in mm, so:Diameter (mm) = EU Size ÷ πWorked example — US size 7 to EU:Diameter = 11.63 + (7 × 0.8128) = 11.63 + 5.69 = 17.32 mm EU size = 17.32 × π = 54.4 mm → rounds to EU 54A US size 7 is therefore EU size 54. Worked example — US size 7 to India: The India ring size table maps inner diameter 17.3 mm to Indian size approximately 15. (Exact values follow the published table used by the Bureau of Indian Standards and major Indian jewellers.) --- ### Dress Size Conversions Dress size conversions use a fixed offset table derived from international fashion industry standards. There is no single physical formula because dress sizes are based on a combination of bust, waist, and hip measurements that do not scale uniformly across brands. The standard offset relationships used in this converter are: | US Size | UK / AU | EU | Italy | Japan | |---------|---------|-----|-------|-------| | 0 | 4 | 32 | 36 | 5 | | 2 | 6 | 34 | 38 | 7 | | 4 | 8 | 36 | 40 | 9 | | 6 | 10 | 38 | 42 | 11 | | 8 | 12 | 40 | 44 | 13 | | 10 | 14 | 42 | 46 | 15 | | 12 | 16 | 44 | 48 | 17 | | 14 | 18 | 46 | 50 | 19 | Worked example — US size 10 to UK and Japan: - US 10 → UK 14 (offset +4) - US 10 → Japan 15 (odd-number scale, counting up by 2 from Japan 5 at US 0) These offsets reflect the most commonly published equivalences. Actual garment measurements vary by brand, and Italian sizing in particular may differ by ±1 size depending on the fashion house.
Frequently Asked Questions
A US ring size is a numerical scale used in the United States and Canada to specify the inner circumference of a ring, typically ranging from size 3 to size 13 in whole and half increments. Each whole size represents a change of roughly 0.8 mm in inner diameter. The scale was standardised by American jewellers and differs from the European ISO standard, which expresses size in millimetres of inner circumference. Knowing your US ring size is essential when purchasing jewellery from North American brands or retailers.
US ring sizes are expressed as unitless numbers (e.g., size 7), while EU / ISO ring sizes represent the inner circumference of the ring in millimetres (e.g., size 54). A US size 7 corresponds approximately to EU size 54, because the inner circumference of that ring is about 54 mm. The two scales are non-linear relative to each other in a practical sense, so a simple addition will not convert them — a lookup table or the diameter-based formula is required. This converter handles the mapping precisely for all common US sizes.
US dress sizes run approximately 4 sizes lower than UK dress sizes on the numeric scale. A US size 8 is roughly equivalent to a UK size 12, a US size 10 to UK size 14, and so on. This difference exists because the two systems were calibrated independently and use different body measurement benchmarks. Always verify with a brand's specific size chart, as vanity sizing means actual garment measurements vary significantly across manufacturers.
US dress size 0 corresponds roughly to EU size 32, which in Indian dress sizing terms is typically labelled XS or size 28 (referencing the waist in inches). Indian ready-to-wear uses a mixture of numeric, alphabetic (XS/S/M/L/XL), and waist-inch labelling depending on the brand. This converter maps US sizes to the most widely used Indian equivalent numbering so you can compare at a glance. Bear in mind that Indian ethnic wear (salwar suits, sarees) follows a different size system and is not covered by this converter.
Select 'US / Canada Ring Size' in the From field, enter your ring size, and choose 'India Ring Size' in the To field — the converter will display the Indian equivalent instantly. Indian ring sizes use a numeric scale similar to UK sizing but with slightly different numerical values, particularly at the lower end of the range. The conversion is based on inner diameter in millimetres as the common intermediate unit. If you are buying from a local jeweller in India, ask them to measure your finger in mm and use the 'Inner Diameter (mm)' unit for the most accurate result.
Select the size system you already know in the 'From' dropdown — for example, 'US / Canada Ring Size' — then select the target system in the 'To' dropdown, such as 'EU / ISO Ring Size'. Enter your current size in the input field and the converted value appears immediately. To switch directions, use the swap ⇅ button between the two dropdowns. You can convert any combination within the Ring Size group or within the Dress Size group.
No — ring sizes and dress sizes are completely unrelated measurement scales, so conversions only make sense within the same group. The converter keeps them in separate groups: Ring Size (US/Canada, EU/ISO, UK/Ireland/AU/NZ, Japan/China/Korea, India, and inner diameter in mm) and Dress Size (US/Canada, UK/Ireland, EU, AU/NZ, Italy, Japan). Select both your From and To units from the same group for a meaningful result.
India uses a numeric ring size scale that broadly follows the UK / Ireland system but with its own numbering convention used by Indian jewellers. Sizes in India typically range from about 0 to 30, with each increment corresponding to a change of about 0.8 mm in inner diameter, similar to the US system. However, the starting number differs, which is why a US size 5 does not equal an Indian size 5. This converter uses inner diameter in millimetres as the bridge to ensure accurate cross-system mapping.
A US dress size 12 corresponds to approximately EU size 42. The EU dress size system is based on bust measurement in centimetres, while the US system uses an abstract numeric scale with roots in historical Misses sizing. The offset between US and EU sizes is not constant — at smaller sizes the gap is about 30 (US 0 ≈ EU 32), while at larger sizes the relationship can shift slightly depending on the brand's fit model. Use this converter as a starting reference and always consult the brand's size guide for a final decision.
The conversions in this tool are based on the most widely published size equivalence tables from jewellery industry standards (ISO 8653 for ring sizes) and international fashion size guides. Ring size conversions are highly reliable because they are rooted in a physical measurement — inner diameter in millimetres. Dress size conversions are approximate because each brand applies its own ease allowances and fit standards, so the same nominal size can vary in actual measurements by 2–3 cm across manufacturers. Treat dress size conversions as a starting point for selecting sizes to try, not a guarantee of fit.
Japan uses a numeric dress size system where sizes typically run 5, 7, 9, 11, 13, 15, 17 — odd numbers only. These correspond to a specific set of bust, waist, and hip measurements standardised by the JIS (Japanese Industrial Standards). A Japanese size 9 is roughly equivalent to a US size 6 or UK size 10. Japanese sizing tends to run smaller than Western sizing, so shoppers ordering from Japanese brands often need to size up compared to their usual Western size.
Australian dress sizes run approximately 4 sizes higher than US sizes, following the same offset as UK sizes. A US size 8 equals roughly an AU size 12, and a US size 14 equals approximately an AU size 18. Australia and New Zealand share the same dress size scale, which is the same as the UK scale. This converter covers both AU and NZ dress sizes under a single 'AU / NZ Dress Size' unit.
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