Ring Size Guide
| Ring Size | Inner Ring (cm) | Diameter (cm) |
|---|---|---|
| 1 | 1.3 | 4.08 |
| 2 | 1.35 | 4.24 |
| 3 | 1.4 | 4.4 |
| 4 | 1.45 | 4.56 |
| 5 | 1.5 | 4.71 |
| 6 | 1.55 | 4.87 |
| 7 | 1.6 | 5.03 |
| 8 | 1.65 | 5.18 |
| 9 | 1.7 | 5.34 |
| 10 | 1.75 | 5.5 |
| 11 | 1.8 | 5.65 |
| 12 | 1.85 | 5.81 |
| 13 | 1.9 | 5.97 |
| 14 | 1.95 | 6.13 |
| 15 | 2. | 6.28 |
| 16 | 2.05 | 6.44 |
| 17 | 2.1 | 6.6 |
| 18 | 2.15 | 6.75 |
| 19 | 2.2 | 6.91 |
| 20 | 2.25 | 7.07 |
| 21 | 2.3 | 7.23 |
| 22 | 2.35 | 7.38 |
| 23 | 2.4 | 7.54 |
| 24 | 2.45 | 7.7 |
| 25 | 2.5 | 7.85 |
Measure without a ring ( Diameter in Table )
Step 1: Cut a thing strip of paper
Step 2: Wrap the paper around your finger. Make sure it's snug. 
Step 3: Mark with a pen where the two end meets.
Step 4: Measure length on a ruler from the tip to pen mark
Measure with a ring ( Inner Ring in Table )

Put the ring on a ruler (centimeter side). Make sure it sits from zero and that you're measuring the inside diameter, not the outside.