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Justin Beaupre/Demand Media

Jewelers often personalize rings according to a customer’s specifications. When rings are engraved or customized in any way, the seller may not be able to accept returns, so you should measure your thumb to obtain your exact ring size before ordering jewelry. Measuring your thumb for a ring is a can be done by yourself at home or by a jeweler.

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Justin Beaupre/Demand Media

Cut a 4-inch length of string or a 4-inch long, thin strip of paper. You can also find and print out a paper thumb gauge online.

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Justin Beaupre/Demand Media

Wrap the paper or string around the base of your thumb. Measure your thumb at the end of the day, when your thumb is the largest. Your body should be room temperature, because cold will cause your thumb to appear smaller, while heat will cause your thumb to expand.

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Justin Beaupre/Demand Media

Move the paper up and over your knuckle to check that it slides off easily. If there is too much resistance, loosen the paper slightly and check again. You want your ring to slide on comfortably, but it shouldn’t be too loose.

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Justin Beaupre/Demand Media

Mark the paper or string where the two ends overlap.

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Justin Beaupre/Demand Media

Straighten the “thumb gauge” and use a ruler to measure the length that wrapped around your thumb. Measure in inches.

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Justin Beaupre/Demand Media

Convert the length of the paper to your ring size. Refer to this conversion chart:

Inches U.S. Ring Size 1 13/16 4 1 15/16 5 2 1/16 6 2 1/8 7 2 1/4 8 2 5/16 9 2 7/16 10 2 9/16 11 2 5/8 12 2 3/4 13 2 7/8 14

Tip

Jewelers will measure your thumb for free as a courtesy.