Fiberglass filters last up to 30 days. Pleated filters can last up to 90 days. Washable filters should be washed every 30 days and last up to 5 years. Mini-pleated filters should be vacuumed every 60 days and will last up to one year. There is no “standard expectancy” for an air filter. It all depends on each home’s characteristics, how many people live there, if there are pets, if there are smokers, how much air pollution and pollen is in your town, etc… The best way to make sure you are changing your air filter on time is to be proactive and regularly check it monthly. Mark it on your calendar, schedule it in your phone, or put a note on the refrigerator.