Experts recommend replacing your mattress about every 7 years, but this is just a guideline. How long your mattress lasts will depend on how you use and care for it. There are several things you can do to increase your mattress's lifespan.
Flip it around regularly.
You've probably heard before that you're supposed to turn your mattress over periodically. However, simply flipping it end-over-end is not enough. Most people sleep on just one side of the mattress, so even if you turn it over periodically, one side is going to get more wear than the other. To ensure more even wear, turn your mattress 180 degrees every couple of months, and also flip it end-over-end every few months.
Keep in mind that turning your mattress 180 degrees is less important if you sleep with a partner. However, if you and your partner are different weights, you should still do this so that the mattress gets even pressure exposure on both sides.
Vacuum your mattress regularly.
It sounds gross, but your dead skin cells sink into your mattress. Dust mites also end up in there. Mattresses actually gain weight as they age, thanks to this accumulation of skin cells and dust mites. The accumulation decreases the flexibility of the mattress and makes it less comfortable over time. (Not to mention, it's just gross and smelly). Vacuuming won't stop this process entirely, but it will slow it down. Make a habit of vacuuming your mattress each time you wash your sheets.
Make sure your mattress is supported properly.
Make sure you purchase a good box spring for your mattress. Generally, purchasing the one that is made to coordinate with the mattress is the best choice, since you can be assured that this one is properly sized and has supports in the proper place for your style of mattress. Sleeping on a mattress on a floor or without a box spring will decrease its lifespan.
In addition to using a box spring, make sure the bed frame you're using offers plenty of support. Simple, metal frames that are nothing more than a rectangle are quite common, but these are not the best choice. Look instead for a bed frame that has several slats running across its width. These add support to the middle of the mattress, keeping it from sagging.
If you follow the tips above, who knows -- your mattress could stay comfortable for 10 years or even longer. For assistance, talk to a professional like Mattress Ranch.