Method
How to calculate estimated annual running cost
The model separates frequency from duration so occasional high-power devices can be compared with always-on equipment.
FORMULAAnnual cost = watts ÷ 1,000 × hours per use × uses per year × tariff
Worked example
Appliance running-cost calculator example
A 900 W appliance used for 2 hours on 250 days consumes 450 kWh annually.
Change one assumption at a time to see what drives the result. The output is an estimate, not a quote, forecast or recommendation.
FAQ
Appliance running-cost calculator FAQ
Should standby power be included?
Add standby consumption as a separate always-on calculation when it is material.
Can I compare two appliances?
Run each appliance with the same tariff and expected life, then compare annual and lifetime totals.
Does this include purchase or maintenance cost?
No. It isolates electricity use so other ownership costs remain visible separately.