9-Watt vs 15-Watt LED Bulb: Running Cost Compared
A 15-watt LED bulb costs $0.158 more per month than a 9-watt LED bulb ($1.92 per year), assuming 5 hours a day at $0.175/kWh. Per hour the difference is $0.001.
Side by side
| 9-watt LED Bulb | 15-watt LED Bulb | |
|---|---|---|
| Power | 9 W | 15 W |
| Hours per day | 5 | 5 |
| Cost per hour | $0.002 | $0.003 |
| Cost per day | $0.008 | $0.013 |
| Cost per week | $0.055 | $0.092 |
| Cost per month | $0.236 | $0.394 |
| Cost per year | $2.87 | $4.79 |
| Energy per year | 16.4 kWh | 27.4 kWh |
Based on $0.175 per kWh (US average).
Which should you choose?
Higher wattage does not always mean more heat or output per dollar, and it does not always mean it runs longer. A bigger unit may reach the target temperature faster and then cycle off. Compare size to your room or job before you decide.
Want your own numbers? Open either calculator and enter your hours and rate: 9-watt LED Bulb or 15-watt LED Bulb.