Measure the diameter of your ring with a tape measure
Let's start with a super easy method. All you need is a ring that fits your finger well and a measuring tape.
1. Place your ring on a table and take your measuring tape.
2. Measure the inner diameter of your ring.
3. Check your ring size in the table.
Measuring the diameter of your finger with a tape measure
If you don't have a ring that fits your finger well, then you could choose to measure the diameter of your finger instead.
1. Put your hand flat on the table and take a measuring tape.
2. Measure the diameter of the finger on which you want to wear your ring.
3. Now that you know how many millimetres the diameter of your finger is, you can read your ring size in the table.