How thick should an inner spring mattress be?

Thick mattresses are a growing trend in inner spring mattress manufacturer—some mattresses are up to two feet thick! But you don't need something that thick in order to be comfortable. Another concern is to keep in mind where you want the mattress to end up. If it's going up a flight of stairs, you can save yourself a lot of back pain by opting for a thinner, lighter mattress that will prove just and comfortable and will probably cost a lot less.