How deep is the Purple™ Mattress Protector? The Purple™ Mattress Protector protects mattresses up to 15 inches tall! Related articles How much is the Purple™ Mattress Protector? Does Purple™ Mattress Protector protect against bed bugs? Does the Purple® Mattress contain any type of phthalate? Why are stretchy sheets so important? How do I wash the Purple™ Mattress Protector?