Cost to Run a 300-watt appliance for 10 hours
Running a 300-watt appliance for 10 hours uses 3 kWh and costs $0.525 at $0.175/kWh. Do that every day and it adds up to $15.75 a month.
Calculate your own cost
- Per hour
- $0.0530.3 kWh
- Per day
- $0.5253 kWh
- Per week
- $3.6821 kWh
- Per month (30 days)
- $15.7590 kWh
- Per year
- $191.631,095 kWh
Formula: watts ÷ 1,000 × hours × rate. Edit any box and every number updates instantly.
People also ask
How much does a 300-watt appliance cost per hour?
At $0.175/kWh, it costs $0.053 per hour. The maths: 300 W ÷ 1,000 = 0.3 kWh per hour, × $0.175 = $0.053.
How much does it cost per month?
Used 10 hours a day for 30 days, it costs about $15.75 per month and uses 90 kWh. Change the hours in the calculator above to match how you use it.
How many kWh does it use?
3 kWh per day, 90 kWh per month and 1,095 kWh per year at 10 hours a day. A kWh is one kilowatt (1,000 W) used for one hour. It is the unit on your electricity bill.
How can I lower the cost?
Use it for fewer hours, switch to a lower-wattage model, and check whether your utility offers cheaper off-peak rates. Enter your own rate above to see the effect.
Does my electricity rate change the answer?
Yes, a lot. At 10¢ per kWh the monthly cost is $9.00 and at 30¢ it is $27.00. Find your rate on your bill (total cost ÷ kWh used) and type it into the calculator.
Cost by hours of use
| Used per day | Energy per day | Cost per day | Cost per month | Cost per year |
|---|---|---|---|---|
| 1 hour | 0.3 kWh | $0.053 | $1.58 | $19.16 |
| 2 hours | 0.6 kWh | $0.105 | $3.15 | $38.33 |
| 3 hours | 0.9 kWh | $0.158 | $4.73 | $57.49 |
| 4 hours | 1.2 kWh | $0.21 | $6.30 | $76.65 |
| 5 hours | 1.5 kWh | $0.263 | $7.88 | $95.81 |
| 6 hours | 1.8 kWh | $0.315 | $9.45 | $114.98 |
| 7 hours | 2.1 kWh | $0.368 | $11.03 | $134.14 |
| 8 hours | 2.4 kWh | $0.42 | $12.60 | $153.30 |
| 9 hours | 2.7 kWh | $0.473 | $14.18 | $172.46 |
| 10 hours | 3 kWh | $0.525 | $15.75 | $191.63 |
| 11 hours | 3.3 kWh | $0.578 | $17.33 | $210.79 |
| 12 hours | 3.6 kWh | $0.63 | $18.90 | $229.95 |
| 13 hours | 3.9 kWh | $0.683 | $20.48 | $249.11 |
| 14 hours | 4.2 kWh | $0.735 | $22.05 | $268.28 |
| 15 hours | 4.5 kWh | $0.788 | $23.63 | $287.44 |
| 16 hours | 4.8 kWh | $0.84 | $25.20 | $306.60 |
| 17 hours | 5.1 kWh | $0.893 | $26.78 | $325.76 |
| 18 hours | 5.4 kWh | $0.945 | $28.35 | $344.93 |
| 19 hours | 5.7 kWh | $0.998 | $29.93 | $364.09 |
| 20 hours | 6 kWh | $1.05 | $31.50 | $383.25 |
| 21 hours | 6.3 kWh | $1.10 | $33.08 | $402.41 |
| 22 hours | 6.6 kWh | $1.16 | $34.65 | $421.58 |
| 23 hours | 6.9 kWh | $1.21 | $36.23 | $440.74 |
| 24 hours | 7.2 kWh | $1.26 | $37.80 | $459.90 |
How we worked it out
- Energy per hour: 300 W ÷ 1,000 = 0.3 kWh
- Cost per hour: 0.3 kWh × $0.175 = $0.053
- Cost per day: × 10 hours = $0.525
- Month and year: × 30 days = $15.75, × 365 days = $191.63
What it costs in different places
Same 300-watt appliance, 10 hours a day. Only the local electricity rate changes.
| Place | Rate per kWh | Cost per month |
|---|---|---|
| United States | $0.175 | $15.75 |
| California | $0.32 | $28.80 |
| Texas | $0.155 | $13.95 |
| New York | $0.25 | $22.50 |
| Florida | $0.155 | $13.95 |
| Illinois | $0.17 | $15.30 |
| Pennsylvania | $0.18 | $16.20 |
| Ohio | $0.17 | $15.30 |
| Washington | $0.115 | $10.35 |
What this estimate assumes
- The appliance draws its full stated wattage the whole time it is on. Real units with a thermostat cycle off and cost less.
- Wattage is the typical label value, not a measured value. Check the label on your own appliance.
- The rate is an approximate residential average. Your bill may include fixed fees, tiers or time-of-use pricing. Edit the rate above.
- A month is 30 days and a year is 365 days.