How much does it cost to run a CFL bulb? ($0.36/mo)
Running a CFL bulb costs about $0.36 / month
($0.01/day at 5 h/day, $0.17/kWh).
($0.01/day at 5 h/day, $0.17/kWh).
Running cost calculator
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A compact fluorescent (CFL) bulb is far more efficient than incandescent but has largely been replaced by even cheaper LEDs.
Cost at different electricity rates
| 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 |
Cost over time
| Per hour of use | $0.00 |
| Per day (5 h) | $0.01 |
| Per month | $0.36 |
| Per year | $4.34 |
How to spend less running a CFL bulb
- Cut the hours: A CFL bulb at 5 h/day runs about $0.36/month — trimming one hour saves roughly $0.07/month.
- Lower the setting: running a CFL bulb on a lower or eco setting drops the wattage directly.
- Upgrade efficiency: a newer CFL bulb near 9 W uses far less than an old 25 W one.
Want the raw figure? See how many watts a CFL bulb uses.
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.