Electricity Cost Calculator
Calculate how much an appliance costs to run based on wattage and usage hours.
How Electricity Bills are Calculated
Electricity is billed in kilowatt-hours (kWh). One kWh = running a 1,000W (1 kW) device for exactly 1 hour. To calculate consumption: kWh = (Watts × Hours per day × Days) / 1,000.
A 100W light bulb running 8 hours/day for 30 days: (100 × 8 × 30) / 1,000 = 24 kWh. At $0.15/kWh, that costs $3.60/month. A 1,500W space heater running 6 hours/day all month: 270 kWh = $40.50/month.
Average US Electricity Costs
The US average residential electricity rate is approximately $0.13–0.16/kWh (2024), with significant state variation: Hawaii (~$0.39), California (~$0.26), Louisiana (~$0.11), Oklahoma (~$0.11). The average US household uses about 900 kWh/month.
Major electricity consumers in a typical home: HVAC (45%), water heater (18%), lighting (9%), washer/dryer (7%), refrigerator (5%). Targeting HVAC and water heating offers the biggest savings.
Reducing Your Electricity Bill
Most impactful changes: switch to LED bulbs (75% less energy than incandescent), upgrade to a smart thermostat (save 10–15% on HVAC), wash clothes in cold water, use power strips to eliminate standby power (phantom load), ensure proper home insulation, run dishwashers and laundry during off-peak hours. Solar panels can offset 50–100% of household electricity depending on location and system size.
Frequently Asked Questions
How much does it cost to run a TV?
A modern 55-inch LED TV uses 60–150W. Running it 5 hours/day at $0.15/kWh costs $1.35–$3.38/month. Older plasma TVs used 300–500W — up to 5x more. OLED TVs vary widely based on brightness.
What uses the most electricity in a home?
Heating and cooling (HVAC) typically accounts for 40–50% of residential electricity use. Water heating, refrigerators, washer/dryers, and lighting follow. In winter climates, an electric space heater running all day can easily double your electricity bill.
What is the difference between kW and kWh?
kW (kilowatt) is a unit of power — the rate of energy use at any instant. kWh (kilowatt-hour) is a unit of energy — the total amount used over time. Your electricity bill charges for kWh, not kW. A 2 kW device running for 3 hours uses 6 kWh.