US sizeDiameterCircumference
414.9 mm46.8 mm
515.7 mm49.3 mm
616.5 mm51.9 mm
6.516.9 mm53.1 mm
717.3 mm54.4 mm
818.1 mm57.0 mm
919.0 mm59.5 mm
Place a ring that already fits on a ruler and measure the inside diameter in millimetres. Match it to the chart — between two sizes, choose the larger one.
We’ll post a reusable plastic ring sizer to you, free. It arrives in 2–3 days with simple instructions.
16.9 mm
Most popular size: 6.5 — highlighted. Measure the inside diameter of a ring that already fits the same finger.
Between sizes? Go up half a size. Resizing is free for life.