Like most equipment, how well you treat your sleeping bag will indicate its lifespan. First of all, it's imperative to treat your sleeping bag with care while camping. Be sure to not aggressively pull your zipper, even if it has an anti-snag feature; stow your bag away with grace; and keep your bag out of damp environments as much as possible, even if it has a water-resistant shell.The way you treat your bag when not camping is equally, if not more, important. Especially if insulated with down, you must store your bag in a cool, dry place and allow the bag to breathe by removing it from its stuff sack. Sleeping bags can last years, even decades. If you're using your bag regularly for extended periods of time, however, it may only last a few years. But if you only camp a few times a year, a good bag can last much of your life.