About us

Ring Size Tool is a free site for finding your size at home, using a strip of paper, a bank card or a ring you already have. The company behind it is Meridian Gauge LLC, 1847 Market Street, Suite 320, Wilmington, DE 19801, United States.

What this sizer does

The sizer converts a single measurement into each common system: US and Canada, UK and Australia, Europe, Japan and India. It also gives the inside diameter and the circumference in mm and inches. We take the sizes from the ring size equivalency table, which follows ISO 8653 and British Standard BS 6820.

Measuring on a screen is a careful guide, but it cannot promise a fit. With an expensive or smart ring, the last check is a jeweller's sizer or a sizing kit from the brand.

Our simple approach

You won't see ads here, you won't need an account and we do not sell rings. The measurements you type never leave your browser.

Contact us

Questions, corrections and requests about your data are all welcome at hello@ring-size-tool.com. Every message gets read.