Size: Beds are measured from outside bumper to outside bumper
X-Small bed measures 17 3/4 " x 11 3/4 " -- Fits crates 18" x 12"
Small bed measures 23 3/4 " x 16 3/4 " -- Fits crates 24" x 17"
Medium bed measures 29 3/4 " x 18 3/4 " -- Fits crates 30" x 19"
Med/Large bed measures 35 3/4 " x 22 3/4 " -- Fits crates 36" x 23"
Large bed measures 41 3/4 " x 27 3/4 " -- Fits crates 42" x 28"
X-Large bed measures 47 3/4 " x 29 3/4 " -- Fits crates 48" x 30"