A bad guest bed usually does not need to be replaced. Most of the time it needs two inches of the right foam on top of it, and that costs a fraction of a new mattress.

Pick the Right Foam

• Memory foam: soft, hugs you, sleeps warmer. Great for side sleepers.
• Latex: bouncier and cooler, firmer feel. Good if you run hot at night.
• Down alternative or fiber fill: the cheapest option. Feels plush but flattens within months.

Thickness Is a Tradeoff

Two inches is the sweet spot for most people. Three inches feels luxurious, but if the mattress underneath is already soft, more foam just means you sink further and wake up stiff. If the mattress is too firm, go thicker. If it is too soft, no topper will save it.

Practical Notes

Measure the mattress before ordering. Guest beds are often a size people assume rather than check. And get a waterproof cover, because a topper absorbs everything and cannot be washed like sheets.

Let it air out flat for a day before you make the bed. New foam smells for the first several hours and it goes away on its own. Ours has been in use for a year with no flat spots, and guests stopped mentioning the bed.