Most mattresses need replacing, on average, after seven years. The original quality of the mattress set, the amount of use and the weight of the sleeper(s) are among the factors that impact the length of time a mattress can sustain comfort and support. A mattress warranty should not be used as an indicator of how long a mattress will provide you with a good night's rest. Our bodies change over time and the quality of the comfort and support a mattress provides should be evaluated every few years as a result.