Get a Strip of Paper or String: Cut a strip of paper or use a piece of string about 1/4 inch (6.35 mm) wide and 4-5 inches (10-12.7 cm) long.

Wrap it Around Your Finger: Wrap the paper or string around the base of the finger where you intend to wear the ring. Make sure it's not too tight or too loose. It should fit comfortably.

Mark the Overlapping Point: Where the end of the paper or string overlaps with the starting point, make a small mark or cut the string. Measure the Length: Use a ruler to measure the length of the paper strip or string in millimeters or inches. Be as precise as possible.

Find Your Size: Use a ring size chart (which can typically be found online) to determine your ring size based on the measurement you obtained.

Tips: Measure your finger in the evening when it's slightly larger, as finger sizes can change throughout the day due to temperature and activity. Measure the specific finger you plan to wear the ring on, as different fingers may have different sizes. Consider the style of the ring. If it's a wide band, you may need a slightly larger size. If your measurement falls between two sizes, it's often better to choose the larger size for comfort.