Light Pollution Calculator
Estimate light pollution from outdoor lighting by calculating wasted lumens, energy cost, and sky brightness impact.
Wasted Lumens
12,000 lumens
Wasted Lumens vs Electricity Rate
Formule
## How to Calculate Light Pollution Light pollution is wasted light that shines upward or sideways instead of illuminating the intended area. ### Formula **Wasted Lumens = Fixtures * Lumens * Uplight %** **Wasted Energy = Total Energy * Uplight %** ### Types of Light Pollution - **Skyglow**: Brightening of the night sky over populated areas - **Glare**: Excessive brightness causing visual discomfort - **Light trespass**: Light falling where not needed - **Clutter**: Excessive groupings of light sources Fully shielded fixtures eliminate uplight and reduce waste by 30-60%.
Exemple Résolu
10 fixtures at 4,000 lumens each, 30% uplight, 50W each, running 10 hours/night at $0.15/kWh.
- 01Wasted lumens: 10 * 4,000 * 30% = 12,000 lumens
- 02Annual energy: 10 * 50 * 10 * 365 / 1,000 = 1,825 kWh
- 03Wasted energy: 1,825 * 30% = 548 kWh
- 04Wasted cost: 548 * $0.15 = $82/year
Questions Fréquentes
How much energy is wasted by light pollution?
The International Dark-Sky Association estimates that at least 30% of outdoor lighting in the US is wasted, costing about $3.3 billion annually and emitting 21 million metric tons of CO2.
How does light pollution affect wildlife?
Artificial light disrupts migration patterns of birds and sea turtles, confuses nocturnal insects, alters predator-prey relationships, and disrupts plant flowering cycles.
What are dark sky friendly fixtures?
Dark sky friendly fixtures are fully shielded (no uplight), use warm color temperatures (under 3000K), and are properly aimed and dimmed. They provide better visibility while reducing waste.