Ring Size Calculator

Take a ring measurement and get the closest size in US, UK, European and Japanese systems, with the band width allowance and a mandrel check.

Inside diameter of the finger or ring mm

Measure across the widest point of a ring that fits, with calipers if you have them.

Band width mm

A band of 4 mm or more fits more snugly than a narrow one at the same size.

Metal

Used for the spring back allowance in the mandrel check.

This is a hot shop or production run

Uses the tighter end of the mandrel allowance for a fast, consistent result.

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Free calculator by Handcraft worked examples and methodology No account, nothing stored.