Electricity Cost Calculator
Find out what any appliance actually costs to run. Enter its wattage, how many hours a day it runs, and your electricity rate — or start from a preset. Results show daily, monthly, and yearly costs.
Per day
$2.12
Per month
$64.47
Per year
$774
12.00 kWh per day · 365 kWh per month
Default rate is the 2026 US residential average (≈17.65¢/kWh per EIA). Your bill's effective rate — total charges ÷ kWh used — is more accurate, since it includes delivery fees and taxes.
How Electricity Cost Is Calculated
Utilities bill by the kilowatt-hour — one kilowatt of power running for one hour. The math is three steps: convert the appliance's watts to kilowatts, multiply by hours used to get kWh, then multiply by your rate.
Formula
Cost = (Watts ÷ 1,000) × Hours × Rate Example (space heater): 1,500 W ÷ 1,000 = 1.5 kW 1.5 kW × 8 h = 12 kWh per day 12 kWh × $0.1765 = $2.12 per day ≈ $64/month
Frequently Asked Questions
How much does it cost to run a 1,500 W space heater?
At the 2026 US average rate of about 17.65¢ per kWh: 1.5 kW × 8 hours = 12 kWh = about $2.12 per day, or roughly $64 a month. Space heaters are among the most expensive appliances per hour of use in any home.
What electricity rate should I enter?
Your actual rate is on your utility bill — divide the total charge by the kWh used to capture taxes and delivery fees. The 2026 US residential average is about 17.65¢/kWh, but states range from under 12¢ (North Dakota) to over 40¢ (Hawaii).
Why is my actual bill higher than the calculated cost?
Bills include fixed monthly service charges, delivery/transmission fees, and taxes on top of the per-kWh energy charge. Some utilities also use tiered or time-of-use pricing, where heavy usage or peak-hour usage costs more per kWh than the base rate.
Do devices in standby mode really add to the bill?
Yes — 'phantom load' from TVs, consoles, chargers, and smart speakers typically adds 5–10% to household electricity use. A device drawing 10 W continuously costs about $15 a year at average rates; a houseful of them adds up to real money.