Electricity Cost Calculator
Every appliance has a wattage printed on its label or spec sheet, and your utility bill states a price per kWh — multiply through the hours and you know exactly what anything costs to run. A 1,500 W space heater for 3 hours a day at $0.17/kWh is about $23 a month; a gaming PC for 5 hours is similar. This calculator does that arithmetic for any device, any rate, any country's billing unit.
The yearly figure is where decisions live: that old second fridge, the dehumidifier in the basement, the always-on server — each line item is one entry away from a number you can act on. The note adds the standby-power reality check (1-2 W around the clock for anything left plugged in), and the share button sends the cost to whoever in the house needs convincing.
How to use
- Enter the device's wattage (check the label), hours per day, and your rate per kWh from the bill.
- Read the monthly cost in the big result, with daily, yearly and kWh figures alongside.
- Share or bookmark — inputs are remembered so you can price out the whole house one device at a time.
Frequently asked questions
How do I calculate the cost of running an appliance?
Watts × hours ÷ 1000 = kWh; kWh × your rate per kWh = cost. A 1500 W heater for 3 h/day at $0.17/kWh: 1.5 × 3 = 4.5 kWh/day → $0.77/day → about $23/month. The calculator shows each step of the math.
How do I find my electricity rate?
It's on the utility bill, stated in ¢ or $ per kWh — often several line items (energy, delivery, taxes) that you can sum. European bills quote the same figure in €/kWh; enter it the same way after converting to your local currency.
How much does it cost to leave something plugged in?
Standby draw is typically 1-2 W around the clock: roughly 9-17 kWh a year, or $1.50-$3 at typical rates — small per device, meaningful across a house full of chargers and set-top boxes. The calculator's yearly line makes each one concrete.
Do space heaters really cost that much to run?
Yes — resistance heating is the most expensive comfort per kWh. A 1500 W heater at 3 h/day runs $20-25/month at US average rates, which is why the calculator's yearly figure surprises people. Compare against the yearly cost of insulation, a heat pump or simply closing doors.