Choosing a ring is hard enough. Getting the size wrong could be disastrous.
We've got you covered. Our method below whilst not perfect will get it near enough.
We would still recommend you pop into a jewellers and get an actual fitting but if you cant then this guid is a good starting point.

Measure A Ring You Already Own
Start by placing the ring on top of the sizing chart or guide, aligning it with the printed circles provided. Look for the circle that most closely matches the size of the ring.
Make sure the inner edge of the ring lines up perfectly with the outer edge of the circle. The circle should be just visible inside the ring, without overlapping or leaving extra space.
If the ring seems to fall between two sizes, always choose the larger one. For example, if the ring size appears to be around 6.5, it’s best to order a size 7 to ensure a comfortable fit for the recipient. It's easier to resize a ring that's slightly too big than one that's too small.