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Electricity cost calculator
Estimate appliance kWh use, daily cost, monthly cost, yearly cost and multi-appliance totals from watts, hours and your local rate.
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No regional currency, unit or language profile is applied. This choice does not convert values or change formulas, results, routes or legal guidance.
Estimated monthly cost
$30.00150 kWh for 1 appliance(s) over 30 days- Daily energy
- 5 kWh
- Daily cost
- $1.00
- Yearly energy
- 1,825 kWh
- Yearly cost
- $365.00
Compare savings scenarios
Change one planning assumption at a time. Negative differences represent estimated savings.
| Scenario | Changed assumption | Monthly cost | Monthly difference | Yearly difference |
|---|---|---|---|---|
| Current inputs | Baseline | $30.00 | — | — |
| 20% lower appliance power | 800 W | $24.00 | −$6.00 | −$73.00 |
| Use one less hour per day | 4 hours/day | $24.00 | −$6.00 | −$73.00 |
| 10% lower electricity rate | 0.18 per kWh | $27.00 | −$3.00 | −$36.50 |
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Verification and calculation details
- Purpose
- Electricity cost calculator
- Variables and units
- Use the labelled fields and units shown in the calculator. Results use those units unless a conversion is stated.
- Formula and method
- The exact formula and worked example are shown below. Deterministic formula executed locally in the browser.
- Assumptions
- Only entered values and stated assumptions are included. Local fees, rules and professional requirements are excluded unless explicitly shown.
- Engine version
- 1.0.0
- Production verification baseline
- Release 63 · source
998803f - Verification run
release-v63-2026-09-20- Last verified
- — Automated release checks passing
Read the Calculation Standard · Report a calculation or source issue
How this calculator works
Energy in kWh = watts × hours ÷ 1,000. Cost = kWh × electricity rate. Total cost = one-appliance cost × quantity × days used.
Variables and inputs
- Appliance power
- Required numeric input. finite numeric value; calculator-specific validation applies.
- Hours used per day
- Optional numeric input. finite numeric value; calculator-specific validation applies.
- Electricity rate
- Optional numeric input. finite numeric value; calculator-specific validation applies.
- Quantity
- Optional numeric input. finite numeric value; calculator-specific validation applies.
- Days used per month
- Optional numeric input. finite numeric value; calculator-specific validation applies.
How to interpret the result
The calculator returns daily energy use in kilowatt-hours, daily electricity cost, monthly electricity use and cost, annual electricity use and cost, one-variable savings scenarios. Read each output against the assumptions you entered, compare alternatives one variable at a time, and use the result as an estimate rather than a promise.
Common mistakes to avoid
- Mixing units or entering a rate as a decimal when the field requests a percentage.
- Rounding intermediate values instead of the final displayed result.
- Leaving out a cost, timing rule or local requirement listed in the assumptions below.
Practical uses
Use the electricity cost calculator to check a real scenario, compare a changed assumption and explain the arithmetic before relying on a quote, specification or decision.
Worked example
A 1,000-watt appliance used for 5 hours per day uses 5 kWh daily. At $0.20 per kWh, one appliance costs $1 per day, about $30 per 30-day month and $365 per year.
Assumptions and limitations
- the appliance draws the entered power for every modelled hour of operation
- the entered price per kilowatt-hour remains constant and excludes fixed charges, taxes and tiered tariffs
- results are estimates; confirm rates, prices, units and professional requirements that apply
Important notes
Results are estimates based on the values entered. Confirm rates, prices, units and professional requirements that apply in your location. Review the Answer Atlas Calculation Standard and corrections policy for formula, privacy and correction rules.
Frequently asked questions
Where can I find an appliance wattage?
Check the rating label, manual or manufacturer specification. Actual power use may vary during operation.
Can I use any currency?
Yes. Enter the electricity price in your local currency per kWh and read the result in that same currency.
Does this include taxes, tiered tariffs or demand charges?
No. It is a private appliance estimate using the rate you enter. Confirm taxes, fixed fees, peak pricing, solar credits and local tariffs separately.