#### mariners1985

##### Rough_Rock

- Joined
- Jan 10, 2009

- Messages
- 4

That''s one of my gf''s rings placed over a dime. What size ring do you think that is? A dime is 17.91 mm in diameter, which is between a 7.5 and an 8.0 ring size (a 7.5 is 17.7 mm; an 8.0 is 18.2 mm).

I did my best to measure the diameter of the dime and the diameter of the ring on my screen (from the inside wall to inside wall of the ring), to find the ratio of one to the other. For example, (these are made up numbers) if the dime is 3.0 inches across on your screen, and the ring is 2.5 inches across (inside wall to inside wall), then we have a ring with a diameter that''s 83.33% of the dime''s diameter. Then, we have 83.33% of 17.91 mm (dime''s diameter in real life) = 14.925 mm = just over a Size 4.0 ring (see table below). That''s not necessarily my guess; just an example of the math.

So, I have my estimate of the ring size using this methodology, but I''d appreciate if anyone else can do the same exercise to confirm my attempt at measuring/calculating. I would greatly appreciate it!

For your info...

Size 3 = 14.0 mm

Size 3.5 = 14.4 mm

Size 4.0 = 14.8 mm

Size 4.5 = 15.2 mm

Size 5.0 = 15.6 mm

Size 5.5 = 16.0 mm

Size 6.0 = 16.45 mm

Size 6.5 = 16.9 mm

Size 7.0 = 17.3 mm.... and it''s clearly not bigger than that.

Thank you very much!