For the same brightness, LED bulbs usually use less electricity than CFL bulbs and last significantly longer.
For full-home lighting estimates, try the WattSizing Calculator.
Quick Answer
At similar light output, an LED bulb often uses 30% to 50% less power than a CFL bulb.
LED vs CFL Power Comparison
| Approximate Brightness | Typical LED Wattage | Typical CFL Wattage | Typical Incandescent Equivalent |
|---|---|---|---|
| 450 lumens | 4 - 6 W | 8 - 11 W | 40 W |
| 800 lumens | 8 - 10 W | 13 - 15 W | 60 W |
| 1,100 lumens | 10 - 14 W | 18 - 23 W | 75 W |
| 1,600 lumens | 14 - 18 W | 23 - 30 W | 100 W |
LEDs generally deliver more lumens per watt, which is why they reduce energy use at equal brightness.
Annual Cost Example
Assume:
- 6 bulbs
- 5 hours/day usage
- electricity at $0.14/kWh
- brightness target around 800 lumens
| Bulb Type | Watts per Bulb | Total Load (6 bulbs) | Annual kWh | Estimated Annual Cost |
|---|---|---|---|---|
| LED | 9 W | 54 W | 98.6 | $13.80 |
| CFL | 14 W | 84 W | 153.3 | $21.46 |
Annual difference: about 54.7 kWh and $7.66 for just six bulbs.
Realistic Lighting Scenarios
Scenario 1: Living Room Evening Use
- 4 bulbs
- 6 h/day
- LED at 10 W vs CFL at 15 W
Daily energy:
- LED:
0.04 x 6 = 0.24 kWh - CFL:
0.06 x 6 = 0.36 kWh
LED saves about 0.12 kWh/day in one room.
Scenario 2: Whole Apartment Lighting
- 14 bulbs
- average 4.5 h/day
- LED 8 W vs CFL 13 W
Daily totals:
- LED:
14 x 8 W = 112 W->0.112 x 4.5 = 0.504 kWh/day - CFL:
14 x 13 W = 182 W->0.182 x 4.5 = 0.819 kWh/day
Difference is roughly 0.315 kWh/day, which adds up over a year.
Beyond Wattage: Other Practical Differences
- LEDs usually last much longer, reducing replacement cost.
- CFLs may contain small amounts of mercury and need proper disposal.
- LEDs reach full brightness instantly and perform better with frequent switching.
- In enclosed fixtures, check bulb heat ratings and manufacturer guidance.
Related reading:
FAQs
Are CFL bulbs still efficient?
Yes, CFLs are much more efficient than old incandescent bulbs, but LEDs are typically more efficient than CFLs.
Is replacing CFL with LED always worth it?
In most homes, yes, especially for lights used many hours per day.
Do dimmers affect savings?
Yes. Compatible dimmable LEDs can reduce energy use further at lower brightness settings.
Which bulb is better for outdoor fixtures?
LED is usually preferred due to better cold-weather performance and longer service life.
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