What does my meter reading cost?
Copy the kWh and the time from your plug-in meter. We turn it into a daily, monthly and yearly cost at your electricity rate, and show every step.
Your meter reading
Example inputsResults update as you type. All costs are in U.S. dollars. See result ↓
Example result — enter your own meter reading
If this period was typical use36 kWh per 30-day month · average draw 50 W
- 1.2 kWh ÷ 24 hours = 0.05 kWh per hour
- × 24 hours = 1.2 kWh per day
- × 30 days = 36 kWh per month
- × $0.1831 per kWh = $6.59 per month
Year = 365 days at the same average. Seasonal appliances (heaters, air conditioners, dehumidifiers) change with the weather, so one reading only describes the period you measured.
↑ Edit inputsHow to take a good reading
- Plug the meter into the wall, then plug the appliance into the meter. Use the outlet the appliance normally uses.
- Leave it for a typical period. At least 24 hours for anything that switches on and off by itself, such as a refrigerator, freezer or dehumidifier. A few days is better.
- Read two numbers before you unplug: the kWh total and the elapsed time. On many meters one button switches between them.
- Enter both above. For a washer, dryer or dishwasher, choose “One complete use” and measure a single full cycle instead.
My meter only shows watts
A watts reading is the power at that moment. If the appliance draws steady power, such as a lamp or fan, use our watts and hours calculator. If the number keeps changing, leave the meter in place and use its kWh total instead. That total already includes the ups and downs.
Why not just use the label?
Labels show maximum or rated power, and EnergyGuide labels describe a standard test. A reading from your own home reflects your settings, room temperature and habits during the time you measured.
Borrowed the meter from a library?
Many public libraries and extension offices lend plug-in meters. This page works with any meter that shows kWh and elapsed time. Kill A Watt is a trademark of P3 International. HomeWattCheck is not affiliated with any meter maker.
Practical energy guides
Standby Power Cost: Calculate the Electricity Used While Idle
Find what devices cost while idle or switched off, using measured watts. Avoid two common mistakes: counting hours twice and confusing a power supply’s rating with what it actually draws.
Humidity & comfortWhat Does It Cost to Run a Dehumidifier 24 Hours a Day?
Compare 24-hour dehumidifier cost scenarios, distinguish compressor runtime from time plugged in, and turn measured daily kWh into a seasonal budget.
Appliance decisionsRefrigerator Replacement Payback: Will Energy Savings Cover It?
Will a new refrigerator pay for itself? Use the yearly kWh from each label, your electricity rate and the real cost of replacing it.