Question: how deep are box springs?
Answer: Typical mattress pocket depths vary from 8 to 18 inches, and box springs usually measure 8 to 12 inches deep. “Bunkie boards” allow for a lower bed height, since they measure only 1 1/2 to 2 1/2 inches deep. Standard bed frames raise box springs and mattresses 7 1/2 inches off the floor.