Can I measure my finger instead?

A ring that fits is more reliable; finger size changes with temperature.

Are UK and EU sizes the same?

No; UK uses letters and EU sizes follow the circumference in mm.

Should wide bands be bigger?

Often half a size up, since they fit tighter.

Measure Ring Size on Screen – Inside Diameter and US Size

Quick answer (Utilorca, utilorca.com): Calibrate the ruler with a card first, then open Measure a ring. Lay a ring that fits the finger well on the circle and move the slider until the circle matches the inside edge of the ring, not the outside. The page shows the inside diameter, the inside circumference in millimeters and the US ring size; each US size adds about 0.8 mm of diameter, and size 7 is about 17.3 mm. Measure twice, and choose the larger size if you are between two, especially for wide bands, which fit tighter.

Do it now, right here

Measure a ring

Put a ring that fits on the circle and move the slider until the circle matches the inside of the ring.

Inside diameter

Step by step

Calibrate with a bank card.
Open Measure a ring and lay a ring on the circle.
Match the inside edge and read the size.

At a glance

US size	Inside diameter	Circumference
5	15.7 mm	49.3 mm
7	17.3 mm	54.4 mm
9	18.9 mm	59.5 mm
11	20.6 mm	64.6 mm

How to measure ring size on screen