Power and energy are different
A watt measures the rate at which an appliance uses power. A kilowatt-hour measures energy over time: using 1,000 watts for one hour equals 1 kWh.
Convert cents into a cost
If electricity is listed at 18 cents per kWh, write the price as $0.18 before multiplying. An appliance using 10 kWh at that price costs $1.80 in energy charges.
Why the bill may not have one simple rate
Bills can separate generation, delivery, riders, taxes, and fixed customer fees. Tiered and time-of-use plans also apply different prices to different amounts or hours, so the advertised energy rate may not equal the all-in variable cost of one more kWh.
- Include per-kWh delivery charges in an appliance estimate.
- Keep fixed fees separate because turning off one appliance may not remove them.
- Use each time period's price for schedulable loads such as EV charging.
State averages versus household rates
EIA state values summarize residential revenue and electricity sales for comparison; they are not offers from a specific utility. Use the state average only when you do not have a bill, then enter your plan's rate for a household estimate.
Rate source and limits
The default rate is the EIA U.S. residential average for April 2026, retrieved July 16, 2026. It is an average revenue per kilowatt-hour, not a quote for your utility plan. Fixed fees, taxes, tiers, and time-of-use prices can change the bill.
Open the EIA source