Home Electricity Usage Calculator

Home electricity usage can be estimated by knowing the wattage of your appliances and how many hours per day each one runs.

The formula:

kWh = (Watts x Hours per day x Days per month) / 1,000
Monthly cost = kWh x Rate per kWh

What a kWh costs: US residential electricity averaged 17.3 cents a kWh across 2025 by EIA’s count and reached 18.8 cents in April 2026. EIA’s 2024 state figures run from about 12 cents in Idaho and Louisiana to almost 43 in Hawaii, so the dollar figures below, worked at 18 cents, are a shape rather than your bill.

Top electricity consumers in a typical home (US dollars at 18 cents a kWh):

• Air conditioning: 3,000–5,000 W, 8 hrs/day in summer = 720–1,200 kWh/month ($130–216)
• Electric water heater: 4,500 W, 3 hrs/day = 405 kWh/month ($73)
• Clothes dryer: 5,000 W, 1 hr/day = 150 kWh/month ($27)
• Refrigerator: 150 W, 24 hrs/day (cycles) = 108 kWh/month ($19)
• Electric oven: 2,500 W, 1 hr/day = 75 kWh/month ($13.50)
• Dishwasher: 1,800 W, 1 hr/day = 54 kWh/month ($9.70)
• Washing machine: 500 W, 1 hr/day = 15 kWh/month ($2.70)
• LED TV (55 inch): 100 W, 5 hrs/day = 15 kWh/month ($2.70)
• LED light bulb: 10 W, 5 hrs/day = 1.5 kWh/month ($0.27)
• Phone charger: 5 W, 3 hrs/day = 0.45 kWh/month ($0.08)

Phantom loads (standby power): Devices that are plugged in but “off” still draw 1–5 watts each. A typical home has 20–40 phantom loads totaling 50–100 watts continuously, which is 36 to 72 kWh a month, about $6.50 to $13.

Energy-saving tips:

• Switch to LED bulbs (they use at least 75% less than incandescent)
• Set the thermostat back 7 to 10°F for eight hours a day, which the US Department of Energy puts at up to 10% a year off heating and cooling
• Run dishwasher and laundry during off-peak hours, if your utility prices by time of day
• Unplug chargers and devices when not in use
• Air dry clothes when possible (a daily hour in the dryer is about $27 a month at 18 cents)

Tip: Check your actual kWh rate on your electricity bill. It is usually on the first or second page as “price per kWh” or “energy charge.”