How Long LED Bulbs Really Last

One of the biggest selling points of LED lighting is longevity. Where an incandescent bulb typically lasted around 1,000 hours, most household LED bulbs today carry a rated lifespan of 15,000 to 25,000 hours — at 3 hours of use a day, that works out to roughly 13 to 22 years before the bulb is expected to fail or fall below usable brightness.

How "Rated Lifespan" Is Actually Defined

LED lifespan ratings aren't based on the bulb suddenly burning out the way an incandescent filament does. Instead, manufacturers and standards bodies like ENERGY STAR define rated life using an L70 standard: the point at which the bulb's light output has dropped to 70% of its original brightness. A bulb can keep functioning past its rated hours, just at reduced brightness, which is why two bulbs installed on the same day can look noticeably different in output years later.

What Shortens Real-World Lifespan

Rated hours assume reasonable operating conditions. Several real-world factors can cut that lifespan significantly shorter:

  • Heat buildup in fully enclosed fixtures, recessed cans, or globes not rated for enclosed use, which stresses the LED driver electronics
  • Frequent on/off cycling, which, while far less damaging to LEDs than it was to incandescent filaments, still adds some wear over time
  • Incompatible dimmers, which can cause the driver to run outside its intended range, leading to flicker and early failure
  • Cheap or off-brand drivers, which are the most common point of failure in a low-cost LED bulb well before the LED chip itself degrades

Why Enclosed Fixtures Need Rated Bulbs

A standard LED bulb installed in a sealed globe or enclosed ceiling fan light kit can run hotter than its design allows, cutting its real lifespan well below the rated hours on the box. Bulbs specifically marked "enclosed fixture rated" are built with driver components designed to handle that extra heat.

Warranty as a Quality Signal

Because rated hours are a lab estimate, the manufacturer's warranty length is a useful practical signal. A 3-year-or-longer warranty suggests the manufacturer has enough confidence in the driver and LED chip quality to stand behind it; bulbs with no stated warranty, common in the cheapest multi-packs, are more likely to fail well before their printed hour rating.

Comparing to Older Bulb Types

For context, a standard incandescent bulb lasts around 1,000 hours, and a halogen bulb typically runs 1,000-3,000 hours. Compact fluorescent (CFL) bulbs land in the middle, at roughly 8,000-10,000 hours. LED's 15,000-25,000+ hour rating is the main reason it has become the default household bulb: fewer replacements, lower long-term cost, and, for ENERGY STAR-certified models, independently verified performance against these standards.