TI:ME Slippers run just a bit larger than Nike. For example, if you are a 10.5 in Nike, you will fit snugly into a size 10 TI:ME.
Do not size down more than a half-size. If you are a 12 in Nike, and we don't offer a 11.5, you would stay with the 12. The elastic laces will keep the slippers snug.