A measurement done at a jewelry store does not guarantee the size is correct. There are several reasons for that. A salesperson might be inexperienced or simply bad at taking measurements. Even an experienced salesperson can be sloppy, especially when they feel that you waste their time without any hope for commission. Nevertheless, anecdotal evidence suggests that Tiffany’s is a good place to get your finger measured. Finger size measured at Tiffany, more often than not, makes the engagement ring fit well. Jewelers can use the following terms describing a finger size: 4-plus equals 4 1/8 5-slant(variations: “scant”, “tight”, “just under”) equals 4 7/8 7-minus equals 6 7/8 When you don’t have a jeweler around to measure your finger, you can wrap a paper strip around the knuckle. It’s going to give you a pretty good idea of what your size is. Sometimes a plastic cable tie is used to get the measurement done. The ring size of an existing ring can be measured with a ring gauge or a ring “stick.”