⚠ Important: For 100% Ring Size Accuracy, visit your local jeweler for an in-person measurement. All tools on this site are estimates only.
Measuring Guide

How to Measure for Ring Size

A practical guide to measuring for ring size using everyday items you already have at home.

Measuring for ring size requires nothing more than a strip of paper or string, a ruler, and our chart. Here's exactly how to do it.

What You'll Need

  • A strip of thin paper (or dental floss / thin string)
  • A pen or pencil
  • A ruler with millimetre markings
  • Our ring size chart (below)

Step-by-Step Instructions

  1. 1
    Prepare your measuring tool

    Cut a strip of paper about 10mm wide. Alternatively use dental floss — it wraps closely and doesn't bunch.

  2. 2
    Wrap around the right finger

    Wrap around the BASE of the finger you'll wear the ring on. It should sit snugly but not cut in. Confirm it passes over your knuckle.

  3. 3
    Mark and measure

    Mark where it meets. Measure that length in mm. This is your circumference.

  4. 4
    Find your ring size in the chart

    Find your mm figure in the Circumference column below. Read across for US, UK, and EU sizes.

Measurement to Ring Size Chart

US / CanadaUK / IRE / AUSEUJapanSwissDiameter (mm)Circumference (mm)
3F444414.144.2
3.5G455514.545.6
4H46.576.514.946.8
4.5I488815.348.0
5J499915.749.3
5.5K50.51110.516.150.6
6L51.51211.516.551.9
6.5M53131316.953.2
7N54141417.354.4
7.5O55.51615.517.755.7
8P57171718.257.2
8.5Q58181818.558.2
9R59191918.959.3
9.5S61212119.461.0
10T62222219.862.2
10.5U63.52423.520.263.5
11V65252520.765.0
11.5W66262621.166.2
12X67.52827.521.567.5
12.5Y68.52928.521.968.8
13Z70303022.370.1
14Z+271313122.771.3

Measuring an Existing Ring

If you have a ring that fits the right finger, place it flat on a ruler and measure the inside diameter — from one inner edge straight across to the other. Use the Diameter (mm) column above to find the size.

Pro tip: Measure three times on three different occasions and use the largest measurement for the best fitting ring.