500-Watt vs 900-Watt Air Conditioner: Running Cost Compared
A 900-watt air conditioner costs $16.80 more per month than a 500-watt air conditioner ($204.40 per year), assuming 8 hours a day at $0.175/kWh. Per hour the difference is $0.07.
Side by side
| 500-watt Air Conditioner | 900-watt Air Conditioner | |
|---|---|---|
| Power | 500 W | 900 W |
| Hours per day | 8 | 8 |
| Cost per hour | $0.088 | $0.158 |
| Cost per day | $0.70 | $1.26 |
| Cost per week | $4.90 | $8.82 |
| Cost per month | $21.00 | $37.80 |
| Cost per year | $255.50 | $459.90 |
| Energy per year | 1,460 kWh | 2,628 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: 500-watt Air Conditioner or 900-watt Air Conditioner.