Choose the reading you have and replace the sample values with your own.
Start with the wattage
Look for watts on the rating plate. Divide by 1,000 and multiply by the hours the appliance actually draws that power. A heater with a thermostat may cycle off while still switched on.
Read the EnergyGuide label
For a refrigerator or clothes washer, use estimated yearly electricity use in kWh and divide by 12 for a monthly average. For a specific wash programme, use the kWh measured for one cycle and multiply by monthly loads.
Measure intermittent use
Record kWh over several typical days with a compatible plug-in meter. Divide by the number of days and multiply by 30. Use only the kWh of one complete run if you want the cost of that run.
In a Fraunhofer ISI test, keeping one litre of water hot at the highest setting took an average of 120 W with a single-wall kettle and 56 W with an insulated kettle. This was the keep-warm phase, after heating.
Find your electricity rate
Check the usage rate on your utility bill or tariff schedule. Include charges that vary with each kWh and use the applicable tier or time window. Enter cents as dollars, so 18¢ becomes $0.18.
