You will need
  • - ruler or caliper;
  • - thread or thin string;
  • - nail clippers;
  • - the table of conformity of sizes of rings.
The Russian system of the size of the rings is based on the inner diameter of the ring. The step size is 0, 5 mm. To determine it at home you can use the calipers. If not this tool, the diameter of the ring can be calculated using a regular ruler.
To find out ring size, remember the formula from a school course of geometry: the circumference is the product of the number π on the diameter. To measure the circumference of your finger, use a strong thread. Wrap it around your finger 4-5 girth at the widest portion thereof. Do not wrap the string tight or overly weak. It should not be felt on the finger.
To make along a few finger movements which twist the thread to each other in the harness. Carefully cut all the layers with scissors. Measure the resulting flagellum with a ruler in millimeters. This will be the circumference of your finger.
To calculate the size of the ring divide this value by the number π equal to 3, 14... the result rounded up to the nearest 0.5 or 1. For example, the calculated diameter was 16.3. Round it up to 16, 5. The result of 17.7 round to the nearest whole number 18. It will be Russian ring size.
There are several dimensional systems for rings. For example, the size range of the rings USA like Russian, only the ring diameter is measured in inches. One inch is equal to 2.54 cm In the UK adopted a letter system of dimension rings. The sizes of the rings are the most popular countries–manufacturers represented in the illustration.