Use this handy gauge set to measure fingers for wide-width rings. Sizes 1–15 are clearly stamped on gauges in half-size increments. Constructed of bright nickel-plated flat stock.
To ensure an accurate ring size (or an accurate size on any circular jewelry piece), add the wire diameter (or the bar-stock thickness) to the finished inside diameter you want and multiply by pi (3.14).
1 Start with the desired inside diameter of the finished ring.
2 Add the wire diameter or metal thickness.
3 Multiply the result by pi (3.14).
4 This is the length of material you will need to cut to achieve your desired final result.