Electricity Cost Calculator

Know Exactly What Your Appliances Cost to Run

Every appliance in your home silently adds to your electricity bill. A space heater running eight hours a day can cost over $40 a month. A forgotten light left on 24/7 adds up over a year. Understanding these costs lets you make informed decisions about which appliances to use, when to use them, and whether upgrading to a more efficient model is worth the investment.

This calculator takes the guesswork out of energy costs. Enter the wattage and usage hours, and see exactly what any appliance costs to operate — daily, weekly, monthly, and annually.

The Math Behind Electricity Costs

Electricity billing is straightforward once you understand the units. Your utility charges by the kilowatt-hour (kWh), which is 1,000 watts used for one hour. To calculate cost, multiply the appliance wattage by hours of use, divide by 1,000 to get kWh, then multiply by your rate.

For example, a 1,500W space heater running 8 hours a day at $0.12/kWh costs: 1,500 x 8 / 1,000 x 0.12 = $1.44 per day, or about $43 per month. That single appliance accounts for a significant portion of many households’ winter electric bills.

Common Energy Costs That Surprise People

Refrigerators run 24/7 but cycle their compressor on and off, so their effective wattage is lower than the rated maximum. A typical refrigerator uses about 150W average, costing roughly $13 per month. Old refrigerators can use 300W or more, making replacement pay for itself in energy savings.

Gaming PCs and home servers draw significant power when running continuously. A 400W gaming PC left on 24 hours costs around $35 per month. Electric vehicle chargers at Level 2 (240V) draw 7,200W or more, though charging sessions are typically just a few hours.

Air conditioning is usually the largest single contributor to summer electricity bills. A central AC unit may draw 3,000-5,000W, and window units typically use 500-1,500W.

Using This Data to Reduce Your Bill

Once you know what each appliance costs, you can prioritize efficiency improvements. Switching from incandescent bulbs to LEDs can reduce lighting costs by 80%. Using a programmable thermostat to reduce AC runtime by two hours a day saves meaningfully over a summer. Running the dishwasher and washing machine during off-peak hours can lower costs if your utility offers time-of-use rates.

The biggest savings usually come from the highest-wattage appliances that run the most hours. Focus there first.