Saving EnergyHow Much Does It Cost to Run an Air Conditioner? (Window and Central AC)
Estimate the cost to run a window or central air conditioner using published wattages and the DOE formula: watts × hours ÷ 1,000 × your rate.
Saving Energy guides
Practical, sourced ways to cut electricity use and what common appliances really cost to run.
Saving Energy
Saving EnergyHow to Lower Your Electric Bill: 12 Practical, Sourced Ways
Practical ways to lower your electric bill, from free thermostat and standby-power fixes to LEDs, insulation and rate plans, each backed by DOE, EPA or EIA guidance.
Saving EnergyPhantom (Standby) Power: What It Costs and How to Cut It
Standby or phantom power can make up 5–10% of home energy use, per DOE. Learn how to measure it, calculate its cost and cut it.
Frequently asked questions
What uses the most electricity in a home?
In homes that use electricity for them, heating, cooling and water heating are usually the largest uses, followed by refrigeration and other appliances (EIA).
How do I work out what an appliance costs to run?
kWh = watts × hours ÷ 1,000; cost = kWh × your rate. Our appliance pages and calculator do this with your state's rate.
Does unplugging devices save money?
Many devices draw a little power on standby. Each one is small, but together they can add up over a year – see our guide to phantom power.