A light bulbs brightness decreases by 10% each year. If it starts at 1000 lumens, what will be its brightness after 5 years?

Tue, 05 May 2026 06:50:20 +0000

**Why Your Home Lighting Fades Over Time—A 5-Year Look at Lumens Loss** Does your lighting feel dimmer than it used to without any change in bulbs? You’re not imagining it. A light bulbs brightness decreases by 10% each year—this gradual fade is subtle but real, securing growing attention across U.S. homes. If your bulbs start at 1,000 lumens, understanding how brightness drops over time helps manage expectations and spot reliable trends in home illumination. With rising energy costs and increasing focus on energy efficiency, many homeowners notice gradual changes in their lighting quality. This 10% annual decrease isn’t just a technical detail—it’s a meaningful factor influencing comfort, safety, and home ambiance. Simplifying a complex process, this decline reflects real-world degradation of light output, not an instant max-out but a steady, predictable loss. **How A light bulbs brightness decreases by 10% each year. If it starts at 1000 lumens, what will be its brightness after 5 years? Actual science confirms the math.** Over five years, a 10% annual drop compounds annually: starting at 1,000 lumens, after one year at 900, then 810, 729, 656, and 590 lumens by year five. This calculation—applied consistently—shows measurable dimming that impacts visibility and design. Though gradual, this trend influences how people choose and maintain lighting across generations of LED and halogen fixtures.