A25 bulbs are the largest type of A-shaped bulb with a diameter of 25 eighths of an inch, or about 3.7 inches. A-shaped bulbs are the most common shape of bulb and are seen in most standard home fixtures. A25 bulbs typically have higher lumens and wattages than other A-shaped bulbs, making them ideal for large home or commercial fixtures such as kitchen lights, vanities, and ceiling lights.
Because of their size and slightly higher wattage, LED A25 bulbs are typically equipped with large heat sinks built into the base to dissipate heat. This makes them unlikely to overheat and last for as long or longer than their expected lifespan. Most LED A25 bulbs are also rated for damp locations, making them equally suitable for indoor and outdoor fixtures.
The lifespan depends on the bulb’s wattage and how often it is drawing power, but typical LED A25 bulbs have up to 50,000 hours of working life. They are longer lasting and more cost-efficient upgrades for traditional incandescent or compact fluorescent A25 bulbs.