There is a simple way to measure size without a ring.

• All you need is a strip of paper, scissors and a pen.
• Cut a strip of paper to the desired size.

An ideal measurement would be about ten centimeters long and about one centimeter wide.

• Place the paper strip around the finger you want to measure and mark where the strip overlaps.
• Then measure the length of the paper strip up to the mark - the measurement in millimeters corresponds to the ring size.

Alternatively, instead of paper, a thread can be used in conjunction with a folding rule or a flexible meter rule for this measuring method.