International Ring Size Conversion

Convert ring sizes between US, UK, European, Japanese, and other international standards with our comprehensive conversion tools and charts.

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Ring Size Conversion Made Simple

Ring sizing systems vary significantly around the world. Whether you're shopping internationally, moving countries, or need to convert a ring size for someone abroad, our comprehensive conversion tools help you find the perfect fit across all major sizing standards.

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Complete International Ring Size Conversion Table

Find your ring size equivalent across all major international sizing systems

Inside Diameter Inside Circumference Sizes
MM Inches MM Inches British & Australian US & Canada French & Russian German Japanese Swiss
9.91 0.390 31.13 1.22 - 0000 - - - -
10.72 0.422 33.68 1.33 - 00 - - - -
11.53 0.454 36.22 1.43 - 0 - - - -
11.95 0.470 37.54 1.48 A 1/2 - - - -
12.18 0.479 38.26 1.51 A 1/2 3/4 - - - -
12.37 0.487 38.86 1.53 B 1 - - 1 -
12.60 0.496 39.58 1.56 B 1/2 1 1/4 - - - -
12.78 0.503 40.15 1.58 C 1 1/2 - - - -
13.00 0.512 40.84 1.61 C 1/2 1 3/4 - - - -
13.21 0.520 41.50 1.63 D 2 41 1/2 13 1/2 2 1 1/2
13.41 0.528 42.13 1.66 D 1/2 2 1/4 - - - -
13.61 0.536 42.76 1.68 E 2 1/2 42 3/4 13 3/4 3 2 3/4
13.83 0.544 43.45 1.71 E 1/2 2 3/4 - - - -
14.05 0.553 44.14 1.74 F 3 44 14 4 4
14.15 0.557 44.45 1.75 F 1/2 3 1/8 - - - -
14.25 0.561 44.77 1.76 F 3/4 3 1/4 - - - -
14.36 0.565 45.11 1.77 G 3 3/8 45 1/4 - 5 5 1/4
14.45 0.569 45.40 1.79 G 1/4 3 1/2 - 14 1/2 - -
14.56 0.573 45.74 1.80 G 1/2 3 5/8 - - 6 -
14.65 0.577 46.02 1.81 H 3 3/4 46 1/2 - - 6 1/2
14.86 0.585 46.68 1.84 H 1/2 4 - 15 7 -
15.04 0.592 47.25 1.86 I 4 1/4 47 3/4 - - 7 3/4
15.27 0.601 47.97 1.89 I 1/2 4 1/2 - 15 1/4 8 -
15.40 0.606 48.38 1.90 J 4 5/8 49 15 1/2 - 9
15.53 0.611 48.79 1.92 J 1/4 4 3/4 - - - -
15.70 0.618 49.32 1.94 J 1/2 5 - 15 3/4 9 -
15.80 0.622 49.64 1.95 K 5 1/8 50 - - 10
15.90 0.626 49.95 1.97 K 1/4 5 1/4 - - - -
16.00 0.630 50.27 1.98 K 1/2 5 3/8 - - 10 -
16.10 0.634 50.58 1.99 L 5 1/2 51 3/4 16 - 11 3/4
16.30 0.642 51.21 2.02 L 1/4 5 3/4 - - - -
16.41 0.646 51.55 2.03 L 1/2 5 7/8 - - - -
16.51 0.650 51.87 2.04 M 6 52 3/4 16 1/2 12 12 3/4
16.71 0.658 52.50 2.07 M 1/2 6 1/4 - - - -
16.92 0.666 53.16 2.09 N 6 1/2 54 17 13 14
17.13 0.674 53.82 2.12 N 1/2 6 3/4 - - - -
17.35 0.683 54.51 2.15 O 7 55 1/4 17 1/4 14 15 1/4
17.45 0.687 54.82 2.16 O 1/2 7 1/4 - - - -
17.75 0.699 55.76 2.20 P 7 1/2 56 1/2 17 3/4 15 16 1/2
17.97 0.707 56.45 2.22 P 1/2 7 3/4 - - - -
18.19 0.716 57.15 2.25 Q 8 57 3/4 18 16 17 3/4
18.35 0.722 57.65 2.27 Q 1/2 8 1/4 - - - -
18.53 0.729 58.21 2.29 Q 3/4 8 1/2 - 18 1/2 17 -
18.61 0.733 58.47 2.30 R 8 5/8 59 - - 19
18.69 0.736 58.72 2.31 R 1/4 8 3/4 - - - -
18.80 0.740 59.06 2.32 R 1/2 8 7/8 - - - -
18.89 0.744 59.34 2.34 R 3/4 9 - 19 18 -
19.10 0.752 60.00 2.36 S 9 1/8 60 1/4 - - 20 1/4

Note: Highlighted rows show the most common ring sizes - US 6 (women's average) and US 9 (men's average)

United States & Canada

Common Size Range

Women's Average
Size 6
Men's Average
Size 9

The US and Canadian systems use numerical sizes starting from 3 and increasing in quarter or half-size increments. This is the most straightforward system as it uses simple numbers.

Size Range: Typically 3-13 for women, 8-15 for men

United Kingdom & Australia

Common Size Range

Women's Average
Size M
Men's Average
Size R 3/4

The UK and Australian systems use letters starting from A and progressing through the alphabet, with half sizes indicated by adding ½ after the letter.

Size Range: Typically F-Q for women, N-Z for men

European Union

Common Size Range

Women's Average
Size 52 3/4
Men's Average
Size 59*

European sizes correspond directly to the internal circumference of the ring in millimeters, making it mathematically precise and easy to understand.

Size Range: Typically 44-62 for women, 54-70 for men

*Note: US size 9 does not have a direct European equivalent in our conversion table

Japan

Common Size Range

Women's Average
Size 12
Men's Average
Size 18

Japanese ring sizes use a numerical system starting from 1, with each increment representing approximately 0.33mm increase in diameter.

Size Range: Typically 4-18 for women, 12-25 for men

Understanding Ring Measurements

All ring sizing systems are based on the same fundamental measurements of the ring's internal dimensions. Here's how different measurements relate to ring size:

Internal Diameter

Measurement in millimeters

The straight-line distance across the inside of the ring at its widest point. This is the most common measurement used by jewelers.

Internal Circumference

Diameter × 3.14159 (π)

The distance around the inside of the ring. European sizes correspond directly to circumference measurements.

Finger Circumference

String/paper method

When you wrap a string around your finger, you're measuring the circumference your ring needs to accommodate.

Ring Mandrel

Professional sizing tool

Jewelers use mandrels marked with different sizing systems to measure existing rings or size new ones.

International Ring Shopping Tips

Before You Buy

  • Always confirm which sizing system the seller uses
  • Ask for diameter or circumference measurements in mm
  • Request a detailed size chart from international sellers
  • Consider ordering a ring sizer from the specific region
  • Account for potential return shipping costs and time

When Converting Sizes

  • Use multiple conversion sources to verify accuracy
  • Remember that half-sizes may not exist in all systems
  • Consider the ring width when converting sizes
  • Factor in seasonal finger size changes
  • When in doubt, size up slightly for comfort

Communication Tips

  • Provide measurements in millimeters when possible
  • Include your finger circumference measurement
  • Mention if you prefer loose or tight fitting rings
  • Ask about the seller's return/exchange policy
  • Request confirmation of the final size before shipping