How tall would you be if you had never cut your fingernails?

Cutting your fingernails doesn’t affect your height; height is determined by genetics and growth factors in the body. Fingernails grow at a rate of about 1/8 inch per month, so even if you never cut them, they wouldn’t contribute to your overall height. The length of your nails is unrelated to the growth of your bones or body structure. Thus, you would be the same height regardless of nail length.