Brazil to US Ring Size
Convert Brazilian ring numbers (aros) to US/Canada sizes — essential for buying rings on Amazon, Etsy, or international jewelry stores.
Common Brazilian Aro to US equivalents
Most adult rings fall between Brazilian aro 12 and 26. Use the calculator below for in-between sizes.
- Aro 14 corresponds to US 5½ (16.1 mm)
- Aro 16 corresponds to US 6¼ (16.8 mm)
- Aro 18 corresponds to US 7¼ (17.7 mm)
- Aro 20 corresponds to US 8 (18.1 mm)
- Aro 22 corresponds to US 8¾ (18.8 mm)
- Aro 24 corresponds to US 9½ (19.5 mm)
How Brazilian Aro numbers work compared to US sizes
In Brazil, ring sizes are described as número do aro (or simply "aro"), typically numbered from 10 to 35. Each step on the Brazilian scale represents a distinct increment in the ring inside circumference.
The US and Canadian standard uses numbers from 3 to 13.5 (including half and quarter sizes) based on inside diameter. Because the two systems use different step sizes, the most accurate way to convert between them is through millimeter measurements of inside diameter or circumference.
When purchasing jewelry from international stores (such as Amazon US, Etsy, or overseas jewelers), convert your Brazilian aro to millimeters first, then select the nearest US half size. If your Brazilian measurement falls between two US sizes, sizing up by a quarter or half size is generally recommended for comfort.
Brazil (Aro) to US ring size reference table
Complete side-by-side comparison across all commercial adult sizes.
| Brazil (Aro)BR | US / Canada SizeUS, CA | Inside Diameter (mm) | Inside Circumference (mm) |
|---|---|---|---|
| Brazil (Aro)BR7 | US / Canada SizeUS, CA3 | Inside Diameter (mm)14.0-14.1 | Inside Circumference (mm)44.0-44.2 |
| Brazil (Aro)BR8 | US / Canada SizeUS, CA3¼ | Inside Diameter (mm)14.5 | Inside Circumference (mm)45.55 |
| Brazil (Aro)BR9 | US / Canada SizeUS, CA3½ | Inside Diameter (mm)— | Inside Circumference (mm)— |
| Brazil (Aro)BR10 | US / Canada SizeUS, CA4 | Inside Diameter (mm)14.8-15.0 | Inside Circumference (mm)46.5-46.8 |
| Brazil (Aro)BR11 | US / Canada SizeUS, CA4½ | Inside Diameter (mm)15.6 | Inside Circumference (mm)49 |
| Brazil (Aro)BR12 | US / Canada SizeUS, CA4¾ | Inside Diameter (mm)— | Inside Circumference (mm)— |
| Brazil (Aro)BR13 | US / Canada SizeUS, CA5 | Inside Diameter (mm)15.6-15.7 | Inside Circumference (mm)48.5-49.3 |
| Brazil (Aro)BR14 | US / Canada SizeUS, CA5½ | Inside Diameter (mm)16.0-16.2 | Inside Circumference (mm)50.5-51.9 |
| Brazil (Aro)BR15 | US / Canada SizeUS, CA6 | Inside Diameter (mm)16.4-16.6 | Inside Circumference (mm)51.5-51.9 |
| Brazil (Aro)BR16 | US / Canada SizeUS, CA6¼ | Inside Diameter (mm)16.8-16.9 | Inside Circumference (mm)52.5-53.08 |
| Brazil (Aro)BR17 | US / Canada SizeUS, CA6¾ | Inside Diameter (mm)— | Inside Circumference (mm)— |
| Brazil (Aro)BR18 | US / Canada SizeUS, CA7¼ | Inside Diameter (mm)17.7-17.8 | Inside Circumference (mm)55.0-55.6 |
| Brazil (Aro)BR19 | US / Canada SizeUS, CA7½ | Inside Diameter (mm)18.0-18.1 | Inside Circumference (mm)55.5-56.6 |
| Brazil (Aro)BR20 | US / Canada SizeUS, CA8 | Inside Diameter (mm)18.1-18.2 | Inside Circumference (mm)57.0-58.12 |
| Brazil (Aro)BR21 | US / Canada SizeUS, CA8½ | Inside Diameter (mm)18.5 | Inside Circumference (mm)58.0-59.1 |
| Brazil (Aro)BR22 | US / Canada SizeUS, CA8¾ | Inside Diameter (mm)— | Inside Circumference (mm)— |
| Brazil (Aro)BR23 | US / Canada SizeUS, CA9¼ | Inside Diameter (mm)19.4 | Inside Circumference (mm)60.0-60.94 |
| Brazil (Aro)BR24 | US / Canada SizeUS, CA9½ | Inside Diameter (mm)19.5-19.7 | Inside Circumference (mm)61.0-62.1 |
| Brazil (Aro)BR25 | US / Canada SizeUS, CA10 | Inside Diameter (mm)19.7-19.8 | Inside Circumference (mm)62.0-63.45 |
| Brazil (Aro)BR26 | US / Canada SizeUS, CA10½ | Inside Diameter (mm)20.3-20.7 | Inside Circumference (mm)63.5-64.6 |
| Brazil (Aro)BR27 | US / Canada SizeUS, CA10¾ | Inside Diameter (mm)— | Inside Circumference (mm)— |
| Brazil (Aro)BR28 | US / Canada SizeUS, CA11¼ | Inside Diameter (mm)21 | Inside Circumference (mm)— |
| Brazil (Aro)BR29 | US / Canada SizeUS, CA11¾ | Inside Diameter (mm)— | Inside Circumference (mm)— |
| Brazil (Aro)BR30 | US / Canada SizeUS, CA12 | Inside Diameter (mm)21.4-21.6 | Inside Circumference (mm)67.5-68.49 |
| Brazil (Aro)BR31 | US / Canada SizeUS, CA12½ | Inside Diameter (mm)21.8-22.0 | Inside Circumference (mm)68.5-69.76 |
| Brazil (Aro)BR32 | US / Canada SizeUS, CA13 | Inside Diameter (mm)22.2-22.3 | Inside Circumference (mm)69.76-70.0 |
| Brazil (Aro)BR33 | US / Canada SizeUS, CA13¼ | Inside Diameter (mm)22.6 | Inside Circumference (mm)— |
| Brazil (Aro)BR34 | US / Canada SizeUS, CA13½ | Inside Diameter (mm)22.9 | Inside Circumference (mm)— |
| Brazil (Aro)BR35 | US / Canada SizeUS, CA13¾ | Inside Diameter (mm)— | Inside Circumference (mm)— |
| Brazil (Aro)BR36 | US / Canada SizeUS, CA14¾ | Inside Diameter (mm)— | Inside Circumference (mm)— |
| Brazil (Aro)BR37 | US / Canada SizeUS, CA15 | Inside Diameter (mm)— | Inside Circumference (mm)— |
| Brazil (Aro)BR38 | US / Canada SizeUS, CA15½ | Inside Diameter (mm)— | Inside Circumference (mm)— |
| Brazil (Aro)BR39 | US / Canada SizeUS, CA16 | Inside Diameter (mm)— | Inside Circumference (mm)— |