How lighting cost is calculated
Cost per year = Bulbs × Watts × Hours per day × 365 ÷ 1,000 × Price per kWh
Bulbs are compared at the same brightness. An 800-lumen bulb draws about 60 W as an incandescent, 14 W as a CFL and 9 W as an LED — so the light you get stays the same while the bill drops.
LED vs. CFL vs. incandescent
20 bulbs at 800 lumens, 3 hours a day, 17.5¢/kWh.
| Bulbs | Watts each | Per year | Rated life |
|---|---|---|---|
| Incandescent | 60 W | $229.95 | 1,000 h |
| CFL (compact fluorescent) | 14 W | $53.66 | 8,000 h |
| LED | 9 W | $34.49 | 15,000 h |
Easy ways to cut lighting costs
- Start with the bulbs you use most — kitchen, living room and outdoor lights.
- Use timers, motion sensors or smart bulbs for porch and closet lights.
- Dimmers save energy with LEDs too; check the bulb is marked “dimmable”.
Frequently asked questions
How much does it cost to light a house?
It depends on the number of bulbs and how long they're on. Twenty 60 W-equivalent LED bulbs used 3 hours a day cost about $34.49 a year at 17.5¢/kWh. The same light from incandescent bulbs costs about $229.95.
How much do I save by switching to LED?
Replacing twenty 60 W incandescent bulbs with 9 W LEDs saves about $195.46 a year in that example. At around $2.50 a bulb, the LEDs pay for themselves in roughly 3 months.
What is a 60 W equivalent LED?
It's an LED bulb that gives the same light — about 800 lumens — as an old 60 W incandescent, while drawing only around 8–10 W. Compare bulbs by lumens, not watts.
Are CFL bulbs still worth using?
CFLs use far less power than incandescent bulbs, but LEDs use less still, last longer, reach full brightness instantly and contain no mercury. When a CFL burns out, replace it with an LED.
How long do LED bulbs last?
Typical LED bulbs are rated for around 15,000 hours or more, versus about 1,000 hours for incandescent bulbs — so you also buy far fewer replacements.
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