Ring Size Converter

Shopping for a ring, especially online or while traveling, can be a confusing experience due to the variety of international sizing systems. A size 7 in the US is not a size 7 in the UK, and European sizes use an entirely different scale. Our Ring Size Converter is the perfect tool to eliminate this confusion. Whether you know your size in one country's standard or have a direct measurement of your finger's diameter or circumference, this calculator will help you find your equivalent size across the globe.

Understanding Different Ring Size Systems

There is no single, universally adopted standard for ring sizing, which is why a conversion tool is so necessary. The primary systems you'll encounter are:

• United States & Canada: Uses a numerical scale, often in half and quarter sizes (e.g., 6, 6.5, 7). This scale is based on the inner diameter of the ring.
• United Kingdom, Australia & New Zealand: Uses an alphabetical scale (e.g., L, M, N). Half sizes are also common (e.g., L ½).
• European (ISO 8653): This is the most straightforward system. The size is simply the inner circumference of the ring in millimeters (e.g., 54.5). Many other countries in Europe and around the world have adopted this standard.
• Japan, China & India: These countries use their own numerical scales that do not directly correlate with US or European sizes.

Our calculator focuses on the most common systems: US, UK, and European.

How to Use the Ring Size Converter

Our tool is flexible, allowing you to find your size from a physical measurement.

1. Enter Your Measurement: Input the number you measured.
2. Select the Unit & Type: This is the most important step. Tell the calculator what your number represents. You can choose from:
   • mm (Diameter): The straight-line distance across the inside of a ring that fits you well.
   • mm (Circumference): The distance around your finger, measured with a string or flexible tape.
   • inches (Diameter): Same as above, but measured in inches.
   • inches (Circumference): Same as above, but measured in inches.
3. Click "Convert Size": The calculator will find the closest match in the standard sizing charts and display your estimated size in the US, UK, and EU systems.

How to Measure Your Finger at Home

For the most accurate results, it's always best to be sized by a professional jeweler. However, you can get a good estimate at home:

• String Method (for Circumference): Take a piece of string or floss and wrap it snugly around the base of your finger. Mark where the string overlaps with a pen. Unwrap the string and measure its length in millimeters or inches with a ruler. This is your circumference.
• Existing Ring Method (for Diameter): Take a ring that already fits you well. Use a ruler to measure the inside diameter of the ring from one side to the other. Be as precise as possible.

A Practical Example

Someone measures the inside diameter of a comfortable ring and finds it to be 18.1 millimeters.

• Input: They enter "18.1" into the calculator.
• Unit Selection: They select "mm (Diameter)" from the dropdown menu.
• Result: The calculator searches its chart and finds that a diameter of 18.1 mm corresponds to a US Size 8, a UK Size Q, and a European Size 57.

Frequently Asked Questions (FAQ)

When is the best time to measure my finger?

Your finger size can fluctuate slightly throughout the day and with changes in temperature. It's best to measure your finger at the end of the day when it's at its largest and at room temperature. Avoid measuring when your hands are cold, as your fingers will be smaller.

What about wide-band rings?

Rings with a very wide band (typically 6mm or wider) will fit more snugly than a narrow band of the same size. It is often recommended to go up a half size for a comfortable fit with a wide band.

Is there a difference between men's and women's ring sizes?

No, the sizing scale is unisex. A size 9 is a size 9, regardless of who is wearing it. However, the range of available sizes and common styles will differ between men's and women's jewelry counters.

Helpful Resources

Complete your look with these other sizing guides:

• Glove Size Calculator - Find your perfect glove size.
• Belt Size Calculator - Get the right fit for your belt.
• mm to inches Converter - For quick measurement conversions.
• Blue Nile - Offers a printable ring sizer and detailed sizing guide.
• Catbird NYC - Provides tips and a sizer tool to help you find your size at home.