Hyatt claims that a king-sized mattress weighs 95 pounds and a two-piece box spring set weighs 66 pounds, even though the weight of a king-sized bed varies depending on the manufacturer, quality, and type of mattress used. The mattress and foundation together weigh 161 pounds.
According to Amerisleep, innerspring mattresses typically weigh less than memory foam or latex foam mattresses. A mattress made of low-density memory foam weighs a little bit more than one made of innersprings.
An innerspring mattress weighs nearly 30% less than a memory foam mattress with a density of more than 4 pounds. An innerspring mattress becomes heavier when a foam pillowtop is added.