Electrical Energy Cost Calculator
Calculate the electricity cost of running an appliance from its power, hours of use and your price per kWh.
Your inputs
Results
Cost for the period
$13.50
- Energy used
- 90 kWh
- Cost per hour of use
- $0.2250
- Cost per year at this daily use
- $164.25
✓Exact calculation — rounded only for display
What this calculator does
Running cost depends on power (watts), time used and your tariff.
Formula and method
Worked example
Calculated by this tool with its default inputs:
Inputs
- Power draw: 1500 W
- Hours used per day: 2
- Days: 30
- Electricity price per kWh: 0.15 (any currency)
Results
- Cost for the period: 13.5
- Energy used: 90 kWh
- Cost per hour of use: 0.225
- Cost per year at this daily use: 164.25
How to read the results
High-power devices used briefly can cost less than low-power devices left on all day.
Assumptions and limitations
- Time-of-use tariffs and standing charges are not included.
These are educational estimates. Electrical, structural and other safety-critical work must comply with local codes and be designed or checked by a qualified professional.
Questions
Where do I find the wattage?
On the appliance label or manual; a plug-in meter gives the actual draw.
Methodology and verification
- Result type
- Exact mathematical calculation (rounded only for display)
- Formula version
- 1.0
- Automated verification
- 2 reference and validation test cases, checked against independently computed values. The site cannot be built if any of them fail.
- Editorial review
- Awaiting human editorial review. The explanation was drafted with AI assistance; the formula and examples are verified by the automated tests above.
Privacy
Everything you enter is calculated in this browser and is not sent to Numerith or anyone else. Inputs are added to a share link only if you choose to include them. Privacy policy