International Ring Size Converters & Fit Tools.
Find your perfect ring size with absolute confidence. Cross-reference US numeric, UK alphabetical, and ISO 8653 metric standards, or print our calibrated true-to-scale PDF ring sizer.
Universal Jewelry Sizing Engine
Interactive CalculatorUS Ring Size to UK / EU Ring Size Calculator
Inside Diameter: 17.32 mm (0.682″) | Circumference: 54.41 mm
7
Quarter StepsN 1/2
Imperial Letter Scale54
Circumference mm15
JIS StandardISO 8653 jewelry sizing calibration. Temperature and knuckle width can cause variation.
Ring Size Converters & Guides.
Dedicated converters, wedding band charts, and printable finger sizers.
Engagement Ring Size Chart & Secret Sizing Guide
How to secretly measure your partner's engagement ring size with international size charts, average sizes, and resizing advice.
EU Ring Size Converter & ISO 8653 Chart
Convert European (EU) ring sizes directly to US and UK sizes based on ISO 8653 inside circumference in millimeters.
How to Measure Ring Size at Home (with Printable Sizer)
Accurately measure your ring size at home using our printable PDF-friendly sizer chart, measuring tape, or the string and ruler method.
Printable Ring Sizer Chart & Measuring Guide (PDF)
Free printable ring sizer PDF with true-to-scale circles and cutout finger wrap strip calibrated with a 50mm ruler check line.
International Ring Size Chart & Measurement Guide
Complete global ring size chart cross-referencing US, UK, EU, and Japanese standards with diameter and circumference dimensions.
US to EU Ring Size Converter
Convert ring sizes from US numerical scale to European inner circumference in millimeters with calibrated diameter chart.
US to UK Ring Size Converter
Convert American numeric ring sizes to British UK letter sizes (A to Z+3) with exact millimeter diameter and circumference measurements.
Wedding Ring Size Chart & Band Width Guide
Wedding band size conversion chart for men and women with band width thickness allowances (2mm to 8mm comfort fit).
Printable Ring Sizer & Circle Chart.
Print this page at 100% scale (no scaling) to measure an existing ring or wrap the paper sizer around your finger.
SizeToolsHub — True-to-Scale Ring Sizing Guide
Standard ISO 8653 Calibration | Verify printer scale before cutting or comparing
Place a physical ruler on the bar below. If it does not measure exactly 50 mm, check your printer settings and disable "Fit to Page" or "Shrink to Fit". Set scale to 100%.
Place a ring that fits the intended finger over the circles below. Match the inside circumference of the ring with the circle. If the ring falls between two sizes, choose the larger size.
Cut along the outer outline of the ruler strip below. Cut a small slit at the marked line [SLIT]. Wrap the pointed end around the base of your finger and slide it through the slit. The number aligned with the slit is your ring size.
International Ring Size Conversion Chart.
Official cross-reference comparison comparing US, UK, European (EU), and Japanese ring sizing standards with inside diameter and circumference measurements in millimeters and inches.
| US / CA | UK / AU | EU (ISO) | Japan | Diameter (mm) | Diameter (in) | Circumference (mm) |
|---|---|---|---|---|---|---|
| 3.0 | F | 44 | 4 | 14.07 mm | 0.554″ | 44.2 mm |
| 3.5 | G | 45 | 5 | 14.48 mm | 0.570″ | 45.5 mm |
| 4.0 | H | 47 | 7 | 14.88 mm | 0.586″ | 46.8 mm |
| 4.5 | I | 48 | 8 | 15.29 mm | 0.602″ | 48.0 mm |
| 5.0 | J 1/2 | 49 | 9 | 15.70 mm | 0.618″ | 49.3 mm |
| 5.5 | K 1/2 | 51 | 10 | 16.10 mm | 0.634″ | 50.6 mm |
| 6.0 | L 1/2 | 52 | 11 | 16.51 mm | 0.650″ | 51.9 mm |
| 6.5 | M 1/2 | 53 | 13 | 16.92 mm | 0.666″ | 53.1 mm |
| 7.0 | N 1/2 | 54 | 14 | 17.32 mm | 0.682″ | 54.4 mm |
| 7.5 | O 1/2 | 56 | 15 | 17.73 mm | 0.698″ | 55.7 mm |
| 8.0 | P 1/2 | 57 | 16 | 18.14 mm | 0.714″ | 57.0 mm |
| 8.5 | Q 1/2 | 58 | 17 | 18.54 mm | 0.730″ | 58.2 mm |
| 9.0 | R 1/2 | 60 | 18 | 18.95 mm | 0.746″ | 59.5 mm |
| 9.5 | S 1/2 | 61 | 20 | 19.35 mm | 0.762″ | 60.8 mm |
| 10.0 | T 1/2 | 62 | 21 | 19.76 mm | 0.778″ | 62.1 mm |
| 10.5 | U 1/2 | 63 | 22 | 20.17 mm | 0.794″ | 63.4 mm |
| 11.0 | V 1/2 | 65 | 23 | 20.57 mm | 0.810″ | 64.6 mm |
| 11.5 | W 1/2 | 66 | 24 | 20.98 mm | 0.826″ | 65.9 mm |
| 12.0 | X 1/2 | 67 | 25 | 21.39 mm | 0.842″ | 67.2 mm |
| 12.5 | Y 1/2 | 69 | 26 | 21.79 mm | 0.858″ | 68.5 mm |
| 13.0 | Z 1/2 | 70 | 27 | 22.20 mm | 0.874″ | 69.7 mm |
Frequently Asked Questions About Ring Sizing.
Everything you need to know before shopping for engagement and wedding rings.
What is the average ring size for women and men?↓
In the United States, the average women's ring size is US 6 to 6.5 (UK L 1/2 to M, EU 52-53). The average men's ring size is US 9 to 10 (UK R 1/2 to T 1/2, EU 60-62).
How do US ring sizes convert to UK letter sizes?↓
US sizes use numbers (e.g. 7.0), while UK sizes use alphabetical letters (e.g. N 1/2). Every full US number increment corresponds to approximately two UK letter steps.
What does European (EU) ring sizing mean?↓
EU ring sizing (ISO 8653) is the simplest and most objective standard: the size number is literally the inner circumference of the ring in millimeters (e.g., an EU 54 has an inside circumference of 54 mm).
Can a ring be resized if I order the wrong size?↓
Most precious metal rings (gold, platinum, sterling silver) can easily be resized up or down by 1 to 2 sizes by a jeweler. Eternity bands with diamonds all the way around, tungsten, and titanium rings cannot be resized.