Since standard and mini cribs are different sizes, you need the right accessories to fit them. For example, a standard crib mattress is 28-inches wide and 52-inches long. A mini crib mattress is 24-inches wide and 38-inches long. You will not be able to use a standard crib sheet on a mini crib, and vice versa. However, Carousel Designs offers bedding to fit both – standard and mini crib mattresses.