To choose the good size of ring, the Maison de Grace provides you with a ring size below that you can print.
To determine the size, arm yourselves with a ring that you can put in the finger, look for the diameter corresponding to the circle line which appears entirely inside the ring and raise/find his/her/its number. In case of hesitation, it is better to choose a size above that a size down. In general the engagement ring and the alliance concern to the annular fouths of the left hand.
You should not forget that our two hands are not completely similar, and that a ring worn within an inch by the right hand will not correspond exactly to the same finger of the left hand. Know that the putting with size is possible but everything depends on the model, on the material and on the set.