How to use Appliance Electricity Cost
Estimate kWh and running cost using power, runtime, duty cycle and your tariff.
- Use measured average watts when possible, or state your rated-power assumption.
- Enter realistic hours and use 100% duty for an already averaged measurement.
- Take the energy rate from your bill and keep fixed charges separate.
Formula & calculation method
Daily kWh = watts ÷ 1000 × hours switched on × duty cycle ÷ 100. Period energy = daily kWh × days. Cost = period energy × price per kWh.
Input reference · 5 fields
These labels describe the calculation’s base units. Supported measurements can switch through the header’s region settings; follow the current workspace labels. Prefilled values are examples.
- Running power (watts)
- Enter a plain number with a decimal point if needed. The workspace shows an illustrative value, not a recommendation.
- Hours switched on each day
- Enter a plain number with a decimal point if needed. The workspace shows an illustrative value, not a recommendation.
- Days in your estimate
- Enter a plain number with a decimal point if needed. The workspace shows an illustrative value, not a recommendation.
- Share of that time drawing this power (%)
- Use 100 for measured average watts. Otherwise enter an estimated duty cycle; this is not a measured value.
- Your electricity rate per kWh
- Use one currency consistently. Fixed charges and taxes are excluded.
A quick example
A 1,000 W device drawing that power for 3 hours/day uses 3 kWh/day. Over 30 days at 0.25 per kWh, the energy-only cost is 22.5 in the entered currency.
Assumptions, edge cases & limits
- Rated power is not always average power. Do not apply a duty-cycle reduction again to an already measured average. Fixed fees, tiered rates and taxes are excluded.
- Hours must be between 0 and 24 per day. A fixed daily duty assumption does not reproduce a changing tariff or measured smart-meter profile.
Questions about Appliance Electricity Cost
Can I estimate appliance electricity cost using my local tariff?
Yes. Enter your price per kWh in the selected currency and a realistic power/time assumption. Fixed charges, tiered tariffs and taxes are excluded, so this is the modeled energy component rather than a complete bill.
What duty-cycle percentage should I use?
Use 100% when the watts already represent measured average power. If you enter on-state power, use a realistic share of the operating time at that power. Do not apply the same cycling reduction twice.
Are my files or inputs uploaded?
Calculation and file processing run in your browser without a processing upload. Downloads go to your device. Choosing a next-step transfer creates a temporary local copy for that workflow. Region preferences are stored separately from tool inputs. See our privacy details.
Can I use this tool for free?
Yes. No signup, subscription or payment is required to use the tool or download its output. File tools have device and size limits; a smaller batch may work better on a phone.
Method & references
Read the underlying method or measurement convention in context. These references do not imply affiliation or endorsement.
Australian Government: energy ratings and running costs ↗Check the assumptions, measurement conventions and actual product or contract terms for your use case.A result or explanation needs correcting? Tell us the tool name and an example.