We use US ring sizes for thimble sizes. Because there are no international standard thimble sizes this seemed like a logical choice for most of our customers. You can request a free flexible plastic ring sizer from us, and follow these instructions, or you can use a jewelry store ring sizer.


Another way to determine size is to make a paper circle about 10 millimeters (3/8″) covering the moon of your fingernail. Cut the circle then measure its length on a rule with millimeter marks.

Measure your finger at the base of the nail for a regular height thimble. Measure between the base of your nail and your first knuckle if the thimble is listed as “tall” in the catalog. Measurements of the thimbles are listed for the back and front of most of the thimbles. The measurements are in millimeters to give you an exact length.

Open thimbles should fit your finger with the tip of your finger touching the inside top of the thimble and your nail clearing the nail guard. The thimble should stay on when your fingers point down. It should feel comfortable, not so snug that you feel your pulse!

We can make adjustments to conform the thimble to the contours of your finger. This is relatively easy at quilt shows with your finger right there and our tools handy, but we can do it by mail too!

If your finger has special contours or if you have large knuckles, please send a photo of your finger (or thumb) you want to use to push your needle, or you can trace your finger with your hand flat on a sheet of paper, and then trace a side view of the same finger. You can mail the paper to us with your order, or send a scanned copy by e-mail to tjthimbles@gmail.com.

For a closed thimble, neither the tip of your finger nor finger nail should touch the inside top of the thimble. Use the same tracing technique described above. A closed thimble may need to be tall and tapered to accommodate long fingernails.

For a thumb, follow these same instructions. Thumbs are usually quite oval and we can adjust the thimble oval for your use. A “thumble” may also need to have its front design adjusted outward to clear the first knuckle.