Key numbers
- kWh per day = watts × hours × quantity ÷ 1,000
- 18 appliance presets with typical running watts
- 855 kWh/month: average US home (EIA, 2023 data)
- 18.2¢/kWh: US residential average (EIA, August 2026)
On this page
How to use the Electricity Usage Calculator
- 1Enter your numbersFill in appliance, your watts (leave 0 to use the typical value) (W), hours per day (h), how many and electricity price (¢/kWh). Every field starts with a typical value you can overwrite.
- 2Check the assumptionsTypical watts are averages. Fridges and AC units cycle on and off, so their average draw is far below the nameplate rating. A plug-in watt meter gives the real number.
- 3Read the resultsThe calculator shows electricity used per month, cost per month, per day, per year and watts used in the estimate, and updates as you type.
- 4Use the resultCompare it with your bill, a quote or a product spec sheet before you buy or install anything.
Results update as you type. Back to the calculator ↑
This electricity usage calculator shows how much power an appliance consumes and what it costs. Pick one of 18 common appliances, or choose “Other” and enter its watts, then set the hours per day and how many you have. It works as an appliance energy calculator and a power consumption calculator in one, giving kWh and dollars per day, month and year.
How appliance electricity usage is calculated
- Watts = the value you enter, or the appliance preset’s typical running watts if you leave it at 0
- kWh per day = watts × quantity × hours per day ÷ 1,000
- kWh per month = kWh per day × 30.42; per year = × 365
- Cost = kWh × price in ¢/kWh ÷ 100 (default 18.2¢, the EIA US residential average for August 2026)
Power consumption is measured in watts (W), the rate of use; one watt is one joule per second (NIST SP 811). Electricity usage over time is measured in kilowatt-hours (kWh), which is what your bill charges for.
Worked example with the default inputs
Defaults: a space heater (1,500 W preset), 6 hours a day, one unit, 18.2¢/kWh.
- Per day: 1,500 × 6 ÷ 1,000 = 9.00 kWh, costing $1.64
- Per month: 9 × 30.42 = 273.8 kWh, costing $49.83
- Per year: 9 × 365 = 3,285 kWh, costing $597.87
That one heater uses about a third of the 855 kWh an average US home used per month in 2023 (EIA Table 5A).
Appliance electricity usage table
Typical running watts and hours are the calculator’s presets. Costs use 18.2¢/kWh. Real models vary, so check the label or measure.
| Appliance | Watts | Hours/day | kWh/month | Cost/month |
|---|---|---|---|---|
| Laptop | 50 | 8 | 12.2 | $2.21 |
| LED TV (55 in) | 100 | 5 | 15.2 | $2.77 |
| Gaming PC | 400 | 4 | 48.7 | $8.86 |
| Electric clothes dryer | 3,000 | 1 | 91.3 | $16.61 |
| Refrigerator (average draw) | 150 | 24 | 109.5 | $19.93 |
| Window air conditioner | 1,000 | 8 | 243.4 | $44.29 |
| Space heater | 1,500 | 6 | 273.8 | $49.83 |
| Electric water heater | 4,000 | 3 | 365.0 | $66.44 |
| Pool pump (1.5 hp single-speed) | 1,500 | 8 | 365.0 | $66.44 |
| EV Level 2 charger (32 A) | 7,700 | 2 | 468.5 | $85.26 |
| Central AC (3-ton) | 3,500 | 8 | 851.8 | $155.02 |
Heating, cooling, hot water and EV charging sit at the bottom of the table for a reason (see how US homes use electricity at EIA Energy Explained): they turn large amounts of electricity into heat, cold or motion for hours each day.
What affects the result
Duty cycle. Thermostat-controlled appliances run only part of the time. The fridge preset already uses an average draw; for AC and heaters, enter the hours the compressor or element actually runs, not the hours the unit is switched on.
Model and age. Efficient models can use much less than the typical value. Check the EnergyGuide label for a rated yearly kWh.
Settings and climate. Thermostat setpoints, insulation and outdoor temperature change heating and cooling use more than any other factor.
Your rate. Swap in the price from your bill, or find your true rate with the cost per kWh calculator.
What is normal electricity usage?
Normal US household use is about 855 kWh a month, or roughly 28 kWh a day, the 2023 average for residential customers (EIA Table 5A). Homes in hot southern states that cool with electricity use more; homes heated by gas in mild climates use less.
To compare yourself fairly, divide the kWh on your bill by the days in the billing period. If your daily figure is well above 28 kWh, the appliance table above shows which loads are the likely cause. For what a kWh is and what it can power, see what a kilowatt-hour is.
How to build a home electricity audit
- List every appliance that runs more than an hour a day, plus anything that heats or cools.
- Note the watts from the label, or use the preset in this calculator.
- Estimate realistic daily hours, separately for summer and winter if they differ.
- Run each through the calculator and add up the monthly kWh.
- Compare the total with your bill’s kWh. A gap usually points to a missing large load or standby use.
Tips to lower your usage
- Add up your top five appliances and compare the total with your bill to find the big loads.
- Get exact costs for any wattage with the electricity cost calculator, or quick conversions with the kWh calculator.
- Once you know your total, size a rooftop array with the solar panel calculator.
- Compare the payoffs in our list of ways to lower your electric bill.
- See the CO2 behind your kWh with the carbon footprint calculator.
References
- Thompson, A. & Taylor, B. N. (2008). Guide for the Use of the International System of Units (SI). NIST Special Publication 811. doi:10.6028/NIST.SP.811e2008
- U.S. Energy Information Administration. Electricity explained: Use of electricity. eia.gov
For the units behind these numbers, read what a kilowatt-hour is. Cutting usage is the cheapest step toward running a home on renewable energy.
FAQ
Frequently asked questions
How do I calculate an appliance's electricity usage?
Multiply the appliance's watts by the hours it runs per day and divide by 1,000 to get kWh per day. Multiply by 30.42 for a month or 365 for a year. A 1,500 W heater for 6 hours uses 9 kWh a day and about 273.8 kWh a month.
Which appliances use the most electricity?
Appliances that make heat or cold and run for hours use the most: central air conditioning, electric space and water heating, pool pumps, electric dryers and EV charging. Using the typical values here, a 3-ton central AC running 8 hours a day uses about 852 kWh a month.
How much electricity does a refrigerator use?
This calculator uses an average draw of 150 W around the clock, which is 3.6 kWh a day and about 109.5 kWh a month, roughly $19.93 at 18.2 cents per kWh. Newer efficient models often use less; the yellow EnergyGuide label lists the rated yearly kWh.
Why use average watts instead of the nameplate rating?
Fridges, freezers, air conditioners and heaters switch on and off with a thermostat, so their average draw over a day is far lower than their maximum. Using the nameplate rating for 24 hours would overstate usage. A plug-in watt meter measures the real average.
How can I measure my actual power consumption?
Plug the appliance into a plug-in electricity usage meter for a few days and read the kWh it records. For hard-wired loads like central AC, use your utility's hourly data or a whole-home energy monitor installed by an electrician.
How is electricity usage measured?
Your utility's meter records energy in kilowatt-hours (kWh), the total power drawn over time. Your bill subtracts the previous reading from the current one to get the kWh used in the period. Smart meters also record hourly use, which many utilities show in their online account.
4 Sources
Last updated October 25, 2026. Part of our renewable energy toolkit. Found an error? Tell us.