How many watts does a CFL bulb use? (14 W)
A CFL bulb uses about 14 W
Typical range 9–25 watts.
Typical range 9–25 watts.
Running cost calculator
Per hour—
Per day—
Per month—
Per year—
Energy/mo—
A compact fluorescent (CFL) bulb is far more efficient than incandescent but has largely been replaced by even cheaper LEDs.
CFL bulb power specs
| Typical running power | 14 W |
| Typical range | 9–25 W |
| Energy use | 0.07 kWh/day · 2.1 kWh/mo |
What affects a CFL bulb's wattage
A CFL bulb is rated around 14 W, but the real figure shifts with a few things:
- Model and rating: A CFL bulb ranges from about 9 W on efficient units to 25 W on larger or older ones — a spread of ~16 W.
- Usage: the real draw depends on the bulb type and brightness.
- Run time: because a CFL bulb typically runs about 5 h/day, hours of use matter as much as raw wattage on your bill.
Running cost at $0.17/kWh
| Electricity rate | Per day | Per month | Per year |
|---|---|---|---|
| $0.10/kWh | $0.01 | $0.21 | $2.56 |
| $0.15/kWh | $0.01 | $0.32 | $3.83 |
| $0.20/kWh | $0.01 | $0.42 | $5.11 |
| $0.25/kWh | $0.02 | $0.53 | $6.39 |
| $0.30/kWh | $0.02 | $0.63 | $7.67 |
| $0.40/kWh | $0.03 | $0.84 | $10.22 |
See the full breakdown of what it costs to run a CFL bulb, or what size power station runs a CFL bulb.
FAQ
How many watts does a CFL bulb use?
About 9-25 watts to match a 40-100 W incandescent.
Are CFLs or LEDs better?
LEDs win - they use less power, last longer and contain no mercury.