Ring Sizer

The Most Accurate Online Ring Measurement Tool

Measure Your Ring Size Online

Select your region and adjust the slider to match your ring's inner diameter. Use our online ring sizer for high accuracy.

Place Credit Card Here
US 7 (17.3mm)

*For best results, place a physical ring on your screen and adjust the slider until the blue circle matches the inner edge of the ring.

International Ring Size Conversion Chart

Use our comprehensive chart to convert between US, UK, EU, and Japanese ring sizes. Finding your perfect fit has never been easier.

Inside Diameter (mm) US Size UK Size EU Size Japan Size
14.0 3 F 44 4
15.0 4 H 47 7
16.5 6 L ½ 51.5 11
17.3 7 N ½ 54.5 14
18.1 8 P ½ 57 16
19.0 9 R ½ 59.5 18
19.8 10 T ½ 62.5 20
20.6 11 V ½ 65 23

Frequently Asked Questions (FAQ)

How can I measure my ring size at home?

You can use our online tool combined with a physical ring or a credit card for calibration. Alternatively, use a piece of string to measure the circumference of your finger and compare it to our diameter chart.

Are online ring sizers accurate?

Yes, if properly calibrated! Our tool uses screen calibration with a standard credit card to ensure the pixels on your screen represent real-world millimeters accurately.

What is the average ring size for women?

The average ring size for most women is between US 5 and 7, with US 6 being the most common.

Expert Tips for Perfect Ring Sizing

  • Time of Day: Measure your finger at the end of the day when it's largest.
  • Temperature: Avoid measuring when you're very cold, as fingers can shrink up to half a size.
  • Knuckle: Ensure the ring will be able to slide over your knuckle comfortably.

Download Our Accurate Ring Sizer App

Need to measure on the go? Download our highly-rated Ring Sizer app for iOS. It's the most reliable way to find your ring size using your phone.

Download on the App Store