The ring size guide converts between US/Canada, UK/Australia, EU/French, Japanese, and metric measurements. Find your size by measuring your finger circumference in millimeters, then locate that measurement in the chart below. Includes measurement tips for getting an accurate fit.
Measure Your Ring Size
- 1.Cut a thin strip of paper about 15cm long
- 2.Wrap it snugly around the base of your finger
- 3.Mark where the paper overlaps with a pen
- 4.Measure the marked length in millimeters
- 5.Find your circumference in the table below
Quick Size Lookup
International Ring Size Chart
| US / Canada | UK / Aus | EU / French | Japan | Circ (mm) | Diam (mm) |
|---|
How to Use the Ring Size Guide
This ring size guide helps you convert between international sizing systems and find your correct ring size from a finger measurement. Use the quick lookup above or scan the full conversion table below.
Ordering Rings from International Sellers
When ordering from UK jewelers, use the UK/Australia column. European and French jewelers typically use the EU system (numbered 44-70). Japanese sizes (1-30) are common in Asian online marketplaces. When in doubt, provide your circumference in millimeters — this is the universal measurement any jeweler can work with.
Common Sizing Mistakes
Measuring in cold weather gives a smaller reading — fingers can shrink by half a size in cold temperatures. Measuring in the morning gives a smaller reading than evening (fluid retention increases through the day). For engagement rings and other important pieces, visit a jeweler in person for a professional sizing — especially if your knuckles are significantly wider than your finger base.
Wide Band Adjustments
For bands 6mm and wider, order half a size (0.5 US) larger than your measured size. For very wide bands (10mm+), go a full size up. The additional surface area of a wide band creates more friction, making the ring feel tighter than a narrow ring of the same diameter.
FAQ
Is this ring size guide free?
Yes, completely free with no signup required.
Is my data safe when using this tool?
Yes. This reference runs entirely in your browser. No data is sent to any server.
How do I measure my ring size at home?
Wrap a strip of paper or thin string around the base of your finger. Mark where the end meets the rest of the strip, then measure that length in millimeters against a ruler. This is your finger circumference. Find that measurement in the circumference column of the chart to find your size.
What is the average ring size for women?
The average ring size for US women is 6 to 7 (about 16.5–17.3mm diameter). For US men, the average is 9 to 10 (about 19–19.8mm diameter). These are averages — sizes vary significantly by body type and which hand you're measuring.
Should I go up or down a half size?
When between sizes, go up a half size for wider bands (6mm or wider) because wide bands fit tighter than narrow ones due to more surface area against the finger. For narrow bands (under 4mm), use your exact measurement. Fingers also swell slightly in heat and shrink in cold — measure at the end of the day for the most accurate fit.
Why does my dominant hand have a different ring size?
Your dominant hand is typically 0.5 to 1 size larger than your non-dominant hand due to increased muscle use and blood flow. Always measure the specific finger on the specific hand where you plan to wear the ring.