Room & Furniture Fit Crib Dimensions (Chart): Standard Sizes + 3/4-Inch Gap RuleHome Size Lab Editorial TeamOctober 28, 2026 Standard crib dimensions: 28 x 52 3/8 in inside, a 27 1/4 x 51 5/8 in mattress, and about 56 x 30 in of floor, plus mini crib sizes, gap math, and clearance.
