Solo Biz Soft Editorial Team Appliances have a running cost that is easy to forget. You can work it out with three numbers: the appliance’s power, how long you use it and what you pay per unit of electricity. Here is how.
Step by step
- Find the power in watts. It is on the label or in the manual. If it shows volts and amps, multiply them.
- Divide watts by 1,000 to get kilowatts.
- Multiply by the hours used to get kilowatt-hours (kWh).
- Multiply by the price per kWh from your bill.
Worked example
A 1,500 W heater used for 2 hours uses 1.5 × 2 = 3 kWh. At 0.25 per kWh that costs 0.75 for the session, or 22.50 over 30 days of use.
Tips for lowering the bill
- Use heavy appliances at lower-price times if your tariff has them.
- Switch off standby power where you can.
- Choose efficient appliances when replacing old ones.
- Remember that thermostats make heaters cycle, so real use may be less than full power.
Use our free electricity cost calculator to work it out. To learn how watts, volts and amps connect, see the Ohm’s law calculator.
Frequently asked questions
How do I find my price per kWh?
Check your electricity bill or your supplier’s website.
What is a kilowatt-hour?
The energy used by a 1,000-watt appliance running for one hour.
Do phone chargers cost much?
Very little. Heating and cooling appliances cost the most.
More free tools: browse all our free calculators.
Estimates only. Actual use varies.