Appliance Running Cost Worksheet
One row per appliance. The wattage is on the rating plate; the rate is on your bill.
BFCBrilliance · bfcbrilliance.com/tools/appliance-running-cost-calculator
The arithmetic
- Kilowatt-hours
- watts ÷ 1000 × hours
- Cost
- kWh × your rate
- Cost per hour of use
- watts ÷ 1000 × rate
- If the plate shows amps
- watts = amps × volts
- Hours in a year
- 8,760
- 1 W of standby
- about 8.8 kWh a year
- ⚠ Label watts are a MAXIMUM
- thermostats cycle on and off
- ⚠ Get the rate from the BILL
- cost ÷ kWh, not the tariff
- ⚠ Electricity only
- gas is a different calculation
Your appliances
| Appliance | Watts | Hours/day | Days/week | $/year |
|---|---|---|---|---|
Your rate
- Bill period
- Electricity cost on the bill
- kWh used
- REAL RATE ($/kWh)
- Peak rate
- Off-peak rate
Finding the money
- Rate worked out from the bill, not the tariff headline
- Rating plate read for the big three: heating, hot water, cooling
- Thermostatted appliances entered as hours HEATING, not hours on
- Anything used rarely but left plugged in checked for standby
- Time-of-use tariff run twice, peak and off-peak
- Old fridge or freezer in a garage or basement not forgotten
- Electric shower and immersion heater included if you have them
- Total compared against the whole bill to see what is unaccounted for
The one number worth memorising
Cost per hour of use does not depend on how often you use something - only on the appliance and your rate. Work it out once for the handful of things that matter and you can price any decision in your head: another hour of the heater, a longer wash, leaving the dryer running.
Standby cuts both ways
A watt of standby is about 8.8 kWh a year - nothing beside a heater. But it is charged for every hour you are NOT using the appliance, so for something used an hour a week it can be most of the annual cost. Do not unplug everything; find the two or three rarely-used things that draw real power while off.