The shelf life of a sleeping bag depends on various factors such as the quality of materials, usage frequency, storage conditions, and maintenance. Generally, a well-maintained sleeping bag can last anywhere from 5 to 15 years. However, it's important to note that over time, the insulation may lose its loft and effectiveness, reducing the bag's overall warmth. Regular cleaning, proper storage, and following the manufacturer's instructions can help prolong the shelf life of a sleeping bag.