How can you work out what your ring size is? A simple way is to tie a piece of string or wool around your finger and measure how many millimetres it is. This will give you the inner circumference of the finger. Then look at the ring size chart for France which uses the ISO standard for ring size (see my earlier post). So if it measures 50mm, you can then compare it with other countries’ ring sizes, making it a size 5 1/4 in the US and a size K in Australia. This method can be a bit hit and miss, as it doesn’t take into account the size of your knuckles, but it can give a rough idea. You can also just place a ring on a piece of paper, draw around the inside of the ring and measure that.

A similar method involves an inexpensive measuring band or strap as in the photo below. This one shows US sizing. You tie the band around your finger, slot the end through the end with the arrow and pull it tight to get your measurement.

Jewellers use a number of tools to identify a ring size. But the tool they use can vary depending on the type of ring band involved. Usually they would use a ring gauge, which is a series of metal rings, labelled with a ring size. One of the ring sets is wider than the other as ring size can vary depending on whether your ring has a thin band like one that would be used on a solitaire ring, or a thick band, like a wedding band.

If you bring in a ring, they can also use a ring gauging stick or mandrel to measure that.

Rings, however, can vary in size depending on the shape of the band or the size of the setting. Rings with thick bands usually need to be a bit larger in ring size than a thin band.

When there is a need to reduce the size of a ring, there are a number of ways this can be done without having to physically cut the ring. To fit a ring to the correct size, jewellers may use sizing beads, that is, small beads, which adjust the size to fit. They work to reduce the size of the band but also to hold the ring upright.

Another way to reduce a ring size is to use a ring insert which fits inside the ring. Some are the shape of a horseshoe, others, like the one below, fits across the base of the ring. Versions of these can be bought without going to a jeweller.

Increasing the size of some rings (but not all) by half a size can be done by a jeweller using a variety of ring stretchers and they can, in some cases, also reduce the size of plain band rings with a ring compressor.