Electricity Cost Calculator
Turn an appliance’s wattage and daily hours into its real cost per day, month and year.
How it works
kWh = watts × hours ÷ 1000 · cost = kWh × rate (¢) ÷ 100 — × 30 for a month, × 365 for a year
A kilowatt-hour is 1,000 watts running for one hour, and it’s the unit your utility bills. Multiply the device’s wattage by its daily hours, divide by 1,000, and you have daily kWh; the rate turns that into dollars. Heat-producing devices (heaters, dryers, kettles) draw the most by far.
Worked example
A 1,500 W space heater running 4 hours a day uses 6 kWh daily. At 17¢/kWh that’s $1.02 a day, $30.60 a month, and about $372 a year.
Frequently asked questions
Is the label wattage what the device actually draws?
The label is the maximum. Many devices cycle or idle below it — a fridge rated 150 W runs its compressor only part of the time. A plug-in watt meter shows the true average draw.
Why is my rate higher than the advertised supply rate?
Bills add delivery charges, taxes and fees on top of the generation rate. Divide your total bill by the kWh used to get your true all-in rate — that’s the number to enter here.
Do 240 V appliances work the same way?
Yes — watts are watts regardless of voltage. A 5,000 W electric dryer on a 240 V circuit still costs 5 kWh × your rate per hour of heating.
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This calculator is for educational purposes. Double-check important results before acting on them.