How do you determine the the life span of a light bulb?

The lifespan of a light bulb is typically determined through standardized testing that measures how long it takes for the bulb to fail under controlled conditions. Manufacturers subject bulbs to continuous operation at specified voltages and temperatures until they burn out. The average lifespan is then calculated based on the number of hours the bulbs lasted before failure. Additionally, factors such as the bulb type (e.g., incandescent, LED, fluorescent) and usage patterns can influence the overall lifespan.