If you manually measure the diameter of your finger, do not forget to leave a little space to ring finger does not compress much, but keep it loose. This is necessary because the size of the fingers, depending on external factors may vary, increasing or decreasing. So hot and humid weather, our hands begin to swell, but because the fingers are increased in diameter. But if you make too much stock in the cold weather, the ring will fall off, which is also inconvenient. In the measurements, it is important to choose a middle ground.
If you are going to buy a thin ring, its size may be smaller than that of the product is wider (larger than 8 mm). For wider accessories need extra space, and for thin space should be slightly smaller.
Remember that the thickness of the fingers on the left and on the right hand is different, and therefore the measurement should be carried out exactly in the fingers of the hand on which you plan to wear jewelry.
If, nevertheless, you could not pick a product of the correct size, it can always be corrected. In many jewelry shops can increase or decrease the ring at 1-1, 5 size.
There are also Viennese, French, British and American sizes are considered along the circumference. If you know the Russian diameter, the length is given by L = D * 3, 14. In any European store you will be asked circumference in millimeters.