Electricity Cost Calculator
Estimate the kilowatt-hour (kWh) power consumption and running cost of household electrical appliances.
About Electricity Consumption Calculations
Utility providers bill consumer electric usage by the kilowatt-hour (kWh), representing 1,000 watts of electrical power sustained continuously for one hour.
Formulas
- Daily Energy (kWh): [ Power (Watts) × Daily Hours ] / 1,000
- Cost: kWh Consumption × Electricity Rate per kWh
Worked Example
Running a 1,500 Watt portable space heater for 4 hours per day at a utility rate of $0.16 per kWh:
- Daily consumption: (1,500 × 4) / 1,000 = 6.0 kWh/day
- Daily operating cost: 6.0 × $0.16 = $0.96
- Monthly cost (30 days): $28.80
- Annual operating cost: $350.40
Frequently Asked Questions
Where can I locate an appliance's wattage rating?
Wattage specifications are stamped on the electrical rating label on the back or underside of the device, or listed in the manufacturer user manual.
How does phantom or standby power affect consumption?
Devices left plugged in on standby (like televisions and microwave clocks) draw continuous trickle power, which can add 5% to 10% to residential electric bills.
What appliances draw the most residential power?
Central heating and air conditioning (HVAC), electric water heaters, clothes dryers, and electric cooking ranges draw the largest share of household power.
Does reducing usage during peak hours save money?
Yes. If your utility company uses Time-of-Use (TOU) billing, shifting high-wattage appliance use to off-peak hours reduces your effective rate.
Calculate in three steps
- 1Enter your valuesUse the fields above and check the units shown beside each input.
- 2Run the calculationSelect Calculate to refresh the result with your latest values.
- 3Review or shareCompare the result, reset the form, print it, or share this page.