Electricity Cost Calculator

How It Works

1. 1

   Enter your electricity rate

   Input your cost per kilowatt-hour (kWh) from your utility bill. The US average is about $0.12/kWh.

2. 2

   Add your appliances

   Select from common presets or enter custom wattage and daily usage hours. Add multiple appliances to see combined costs.

3. 3

   Review daily, monthly, and yearly costs

   See the energy consumption in kWh and estimated cost for each time period. Compare appliances to find the biggest energy consumers.

Understanding Electricity Costs

Electricity is one of the largest recurring household expenses, yet most people have little idea how much individual appliances cost to run. The fundamental calculation is simple: multiply an appliance's power consumption (in watts) by its daily usage hours, divide by 1,000 to convert to kilowatt-hours (kWh), then multiply by your utility rate per kWh. A standard refrigerator running 24 hours a day at 150 watts consumes about 3.6 kWh daily — roughly $0.43/day or $13/month at the US average rate of $0.12/kWh. Space heaters and air conditioners are among the most expensive appliances to operate: a 1,500W space heater used 8 hours per day costs over $45/month. Understanding these costs helps you make informed decisions about energy efficiency upgrades, usage habits, and whether to replace older appliances with Energy Star rated alternatives. Our calculator supports multiple appliances simultaneously, so you can estimate your total electricity footprint and identify which devices are driving your bill.

Common pitfalls

• kW is power (the rate at which a device draws energy); kWh is energy (the total used over time). A 1.5 kW space heater running 8 hours consumes 12 kWh. Nameplate wattage tells you the draw; the utility bills kWh.

• Tiered rate structures mean the 1,001st kWh can cost more than the 500th. California IOUs price Tier 2 roughly 25-40% above Tier 1 once you exceed the baseline allowance. Summer AC can push usage into a tier you avoid the rest of the year.

• Time-of-use plans charge 1.5-3x more during 4-9 PM on summer weekdays. PG&E's E-TOU-C tariff ran about $0.60/kWh peak vs. $0.49 off-peak in summer 2025. Shifting dishwasher, laundry, and EV charging to off-peak windows cuts 15-25% off the bill.

• 'Phantom' standby load runs 5-10% of a typical US residential bill. Fifteen idle devices drawing 5 W each sum to about 660 kWh/year, roughly $110 at the 2024 US residential average near $0.164/kWh (EIA). Smart plugs kill the draw when the device is off.

• Utility bills split into 'delivery' and 'generation' charges, both per-kWh. Looking only at the generation rate undercounts the true price by 30-50%. Add both to get the cost per kWh you are actually paying.

Frequently Asked Questions

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