A ring should go over the knuckle but still be comfortable. There should be a tug to get the ring off but not fly off the knuckle with no resistance. I strongly recommend avoiding printable ring sizers or sizers that company’s mail you. Get sized locally any store, walmart, target, or mall jewelry store can quickly size you. In the industry we use an international sizing chart so you dont need to worry about sizes running big or small. The circumference and diameter from jewelry size should be the same. I would advise industry tolerance is about 1/4 size up or 1/8th size down. What can affect different ring sizes is the width of a ring. A wider ring will fit more snug than an a thinner band. Adjust accordingly. 8mm and larger should be about 1/2 size larger from what your sized on locally unless they are sizing you on the same width band your’re ordering. Good news, at Pompeii3 we offer free sizing for 3 months so if you receive a ring that does not fit perfectly simply send it back and we will take care of it. Show Pompeii3 wedding bands here.