Electricity Cost Calculator
Calculate monthly electricity bills from kWh usage and your local rate. See appliance-by-appliance cost breakdown and sa
Appliance Details
Electricity Rate
Daily Cost
10.80 kWh
Monthly Cost
324.0 kWh
Annual Cost
3888 kWh per year
CO₂ Emissions
Per year
Efficiency Savings
Less efficient
How it works
An electricity cost calculator finds what running a device costs. Convert its wattage to kilowatts, multiply by the hours used to get kilowatt-hours, then multiply by your utility's price per kWh.
Running cost
Cost = (watts ÷ 1000) × hours × price per kWh
- watts
- device power draw
- hours
- time used
- price
- your electricity rate per kWh
Worked example
- 1,000 W appliance
- 5 hours/day, $0.15/kWh
- Daily kWh = (1000 ÷ 1000) × 5 = 5
- Cost = 5 × 0.15
$0.75/day (≈ $22.50/month).
Good to know
- Always-on devices (fridges, routers) cost more cumulatively than their low wattage suggests — multiply by 24×30.
- Check your bill for the real per-kWh rate, including delivery charges and time-of-use pricing.
- Standby 'phantom' loads add up; switching off idle electronics trims the bill.
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Frequently Asked Questions
How do I calculate the cost to run an appliance?
Convert to kilowatt-hours — watts × hours of use ÷ 1000 — then multiply by your electricity rate. A 1,500 W space heater running 4 hours a day uses 6 kWh, which at $0.15/kWh costs $0.90 per day, about $27 a month.
What is a kilowatt-hour?
The energy of using 1,000 watts for one hour — the unit your utility bills you for. Ten hours of a 100 W device, one hour of a 1,000 W microwave, and 20 hours of a 50 W fan are each exactly 1 kWh.
Which appliances cost the most to run?
Heating and cooling dominate most bills, followed by water heaters, clothes dryers, and older refrigerators. Always-on "phantom" loads from electronics on standby can also add several percent to a typical household bill.
Why doesn't my bill match the calculation?
Utility bills add fixed monthly charges, taxes, and delivery fees on top of the per-kWh energy rate, and some utilities use tiered or time-of-use pricing where the rate changes with usage or hour. Use your bill's effective rate — total cost ÷ total kWh — for realistic estimates.
How can I lower my electricity costs?
Target the big loads first: thermostat setbacks, a heat-pump or efficient HVAC service, water heater temperature at 120°F, and full loads in dryer and dishwasher. LEDs, smart power strips for standby loads, and shifting use to off-peak hours (on time-of-use plans) compound the savings.