Cost to Run a 20-watt tablet charger for 10 hours
Running a 20-watt tablet charger for 10 hours uses 0.2 kWh and costs $0.035 at $0.175/kWh. Do that every day and it adds up to $1.05 a month.
Calculate your own cost
- Per hour
- $0.0040.02 kWh
- Per day
- $0.0350.2 kWh
- Per week
- $0.2451.4 kWh
- Per month (30 days)
- $1.056 kWh
- Per year
- $12.7873 kWh
Formula: watts ÷ 1,000 × hours × rate. Edit any box and every number updates instantly.
People also ask
How much does a 20-watt tablet charger cost per hour?
At $0.175/kWh, it costs $0.004 per hour. The maths: 20 W ÷ 1,000 = 0.02 kWh per hour, × $0.175 = $0.004.
How much does it cost per month?
Used 10 hours a day for 30 days, it costs about $1.05 per month and uses 6 kWh. Change the hours in the calculator above to match how you use it.
How many kWh does it use?
0.2 kWh per day, 6 kWh per month and 73 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 the actual charging duration for a closer estimate. Check your bill for the exact rate and enter it above.
Does my electricity rate change the answer?
Yes, a lot. At 10¢ per kWh the monthly cost is $0.60 and at 30¢ it is $1.80. 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 | 0.02 kWh | $0.004 | $0.105 | $1.28 |
| 2 hours | 0.04 kWh | $0.007 | $0.21 | $2.56 |
| 3 hours | 0.06 kWh | $0.011 | $0.315 | $3.83 |
| 4 hours | 0.08 kWh | $0.014 | $0.42 | $5.11 |
| 5 hours | 0.1 kWh | $0.018 | $0.525 | $6.39 |
| 6 hours | 0.12 kWh | $0.021 | $0.63 | $7.67 |
| 7 hours | 0.14 kWh | $0.025 | $0.735 | $8.94 |
| 8 hours | 0.16 kWh | $0.028 | $0.84 | $10.22 |
| 9 hours | 0.18 kWh | $0.032 | $0.945 | $11.50 |
| 10 hours | 0.2 kWh | $0.035 | $1.05 | $12.78 |
| 11 hours | 0.22 kWh | $0.039 | $1.16 | $14.05 |
| 12 hours | 0.24 kWh | $0.042 | $1.26 | $15.33 |
| 13 hours | 0.26 kWh | $0.046 | $1.37 | $16.61 |
| 14 hours | 0.28 kWh | $0.049 | $1.47 | $17.89 |
| 15 hours | 0.3 kWh | $0.053 | $1.58 | $19.16 |
| 16 hours | 0.32 kWh | $0.056 | $1.68 | $20.44 |
| 17 hours | 0.34 kWh | $0.06 | $1.79 | $21.72 |
| 18 hours | 0.36 kWh | $0.063 | $1.89 | $23.00 |
| 19 hours | 0.38 kWh | $0.067 | $2.00 | $24.27 |
| 20 hours | 0.4 kWh | $0.07 | $2.10 | $25.55 |
| 21 hours | 0.42 kWh | $0.074 | $2.21 | $26.83 |
| 22 hours | 0.44 kWh | $0.077 | $2.31 | $28.11 |
| 23 hours | 0.46 kWh | $0.081 | $2.42 | $29.38 |
| 24 hours | 0.48 kWh | $0.084 | $2.52 | $30.66 |
How we worked it out
- Energy per hour: 20 W ÷ 1,000 = 0.02 kWh
- Cost per hour: 0.02 kWh × $0.175 = $0.004
- Cost per day: × 10 hours = $0.035
- Month and year: × 30 days = $1.05, × 365 days = $12.78
What it costs in different places
Same 20-watt tablet charger, 10 hours a day. Only the local electricity rate changes.
| Place | Rate per kWh | Cost per month |
|---|---|---|
| United States | $0.175 | $1.05 |
| California | $0.32 | $1.92 |
| Texas | $0.155 | $0.93 |
| New York | $0.25 | $1.50 |
| Florida | $0.155 | $0.93 |
| Illinois | $0.17 | $1.02 |
| Pennsylvania | $0.18 | $1.08 |
| Ohio | $0.17 | $1.02 |
| Washington | $0.115 | $0.69 |
About tablet charger running costs
Tablet charging power changes as the battery fills and depends on the adapter and device. The maximum charger rating is not the average.
Typical sizes: 10 W, 20 W, 30 W, 45 W.
How to spend less: Use the actual charging duration for a closer estimate.
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.