Global Electricity Cost Calculator: Compare Appliance Costs & Savings
How much does it cost to run an appliance?
Enter your electricity price, the appliance's electrical power and the hours you use it each day. See your estimated cost per day, billing period and year.
Electricity cost calculator
Start with your price per kWh, watts, and hours per day. Everything else is optional. Your estimate updates as you enter valid values; use the button to jump to the results.
Step 1 — Your electricity price
Choose your country for the currency, then enter the price per kWh from your electricity bill. We do not guess your tariff.
Billing days and extra charges (optional)
The rate must be in the selected currency per kWh (for example, 20 cents = 0.20 dollars). Currency changes clear earlier monetary inputs; no conversion is performed.
Step 2 — Your appliance
Look for input watts (W) on the device label. Enter how many hours it actually runs in a typical day.
Air conditioner
More options: quantity, days per week, power usage
For devices that cycle on and off, use average measured watts or a documented load factor. Your default is 1 device, 7 days a week, 100% load factor.
Optional: compare a lower-power replacement
Payback compares the two power ratings at the same original schedule and tariff, without attributing time-of-use changes to the replacement.
Sample values are illustrative only: 1,000 W, 5 hours/day, USD 0.20/kWh. No national tariff is assumed.
Compare more appliances (optional)
Add up to 20 appliances. Each card uses the same tariff and the total is shown together.
Your estimated electricity cost
Fill in the price per kWh, appliance watts and hours used per day, then choose Calculate electricity cost.
Go to the calculatorCurrent usage
Bill-period energy + fixed fee—Annual total: —Annual energy: —Scenario after changes
Bill-period energy + unchanged fixed fee—Annual total: —Annual money difference: —Where your potential savings come from
Appliance cost comparison
Bars show each appliance's share of variable bill-period energy costs before changes, including the optional percentage charge but excluding the fixed fee. Sorted by cost, highest first.
Your comparison chart will appear here after you enter inputs.
The CSV includes all tariff, schedule and scenario inputs plus calculated appliance costs and bill totals, so the estimate can be reproduced.
Want to save money? Compare changes (optional)
These are adjustable what-if scenarios, not predictions. Optional replacement watts are set for each appliance above. The controls below apply to each included appliance.
Savings decomposition follows this order: replacement power first, reduced hours second, tariff-period shifting third. A scenario can also increase cost if the replacement draws more power or off-peak power is more expensive.
How to calculate electricity cost from watts and kWh
Appliance power is measured in watts (W), while the energy you pay for is measured in kilowatt-hours (kWh). A higher wattage or longer runtime raises energy use when everything else stays the same.
Find electrical input watts
Check the appliance label, manual or a plug-in energy meter. Use electrical input watts, not heating or cooling output in BTU/h.
Record actual running hours
Enter daytime and nighttime hours plus days used per week. Reduce the load factor only when a defensible average is available for a cycling device.
Use the rate on your bill
Enter the price per kWh in your selected currency. For a time-of-use plan, use separate peak and off-peak rates instead of a blended rate.
Worked example: a 1,000 W appliance for 5 hours per day
This is a hypothetical teaching example, not an observed appliance measurement or a representative national tariff. Assume a flat rate of USD 0.20/kWh, daily use, no fixed fee and no extra charges.
The calculation changes with your actual rate, quantity, running schedule and load factor. Fixed fees, percentage energy charges and scenario assumptions are applied separately in the interactive calculator.
Air conditioners and refrigerators
Compressor equipment can cycle or change its electrical draw. Use measured average watts or a documented duty cycle instead of treating peak input power as continuous consumption.
Why the estimate may differ from your bill
Taxes, tiered pricing, seasonal schedules, demand charges, billing adjustments and energy used by appliances you have not entered can all change the final bill.
Calculation methodology and limitations
Energy use
Average daily kWh = (input W ÷ 1,000) × (day h + night h) × quantity × (load factor ÷ 100) × (days used per week ÷ 7).
Bill-period kWh = average daily kWh × selected billing days. Annual kWh = average daily kWh × 365.
Variable cost and bills
Daily energy cost = (W ÷ 1,000) × quantity × load factor × days/week ÷ 7 × [(day hours × day rate) + (night hours × night rate)] × (1 + optional percentage charge ÷ 100).
Period estimate = daily energy cost × billing days + fixed fee. Annual estimate = daily energy cost × 365 + 12 × fixed fee.
Savings scenarios
Scenario power uses replacement watts if entered; otherwise current watts. Operating hours are reduced by the slider percentage; then available peak hours move to off-peak, capped at the selected shift. Savings are baseline minus scenario, with fixed charges unchanged.
Replacement payback
Simple payback in months = total replacement cost ÷ (annual energy-cost difference from power change only ÷ 12). If replacement power does not save money, no payback is reported. Purchase cost must be supplied by the user.
Scope: these outputs are calculated values from observed or user-estimated inputs, not official projections. The tool assumes the entered running watts and load factor represent each appliance during operating hours. It does not independently measure electricity use, estimate country tariffs, convert currencies, model progressive or demand-based tariffs, account for seasonal schedule changes or include other bill charges that you did not enter. Changing currency clears all monetary inputs without converting their amounts. For thermostatic and inverter devices, measured kWh or average electrical draw is more reliable than maximum nameplate watts. Currency selection changes formatting only.
Frequently asked questions
How do I calculate electricity cost from watts?
Divide watts by 1,000 to obtain kW, multiply by hours used to obtain kWh, then multiply by your electricity price per kWh. This tool also accounts for quantity, operating days and load factor.
Why do I have to enter the price per kWh?
Electricity prices differ by utility, location, contract, time of use and tax treatment. Selecting a country changes the suggested currency but never supplies an unverified tariff.
What should I enter for an air conditioner or refrigerator?
Use measured electrical consumption or average input watts. Compressor-driven devices cycle and may draw less than their rated maximum; alternatively reduce the load factor to reflect your measured or documented duty cycle. Cooling capacity in BTU/h is not electrical input watts.
How do peak and off-peak rates work?
Enter the actual two energy rates and split daily appliance runtime between the corresponding hours. In flat-rate mode both hour fields are charged the same. This model assumes those entered hours occur within the contract's applicable tariff windows.
Does the annual estimate assume a 30-day month?
No. Annual variable energy uses 365 average calendar days. The monthly figure uses the selected 28–31 days; annual fixed charges are applied 12 times.
Is the estimated saving a guaranteed reduction on my bill?
No. It is the mathematical difference between your entered baseline and hypothetical scenario. Actual consumption can change with weather, settings, occupancy, variable power draw and tariff design. Unchanged fixed charges do not contribute to savings.
How is replacement payback calculated?
The payback uses the one-time replacement price and the annual difference in electricity cost between the two wattage values at the original operating schedule. It does not include financing, repairs, rebates or changes to operating hours.
Can I compare appliances in any country or currency?
Yes, by supplying a local tariff and selecting a listed currency or entering a recognized ISO 4217 code. Changing currencies clears old monetary amounts so that they cannot be silently treated as amounts in the new currency. No exchange-rate conversion is performed.
Sources and method references
Virginia Cooperative Extension / Virginia Tech
Methodology reference. Explains watts-to-kWh conversion, operating hours, annual energy and cycling loads. No country tariffs or appliance values are imported into the tool.
https://www.pubs.ext.vt.edu/2901/2901-9014/2901-9014.htmlHawaiian Electric
Methodology reference for nameplate wattage, runtime and billed-energy cost. It also explains thermostatic cycling. The calculator does not use Hawaiian Electric prices.
https://www.hawaiianelectric.com/products-and-services/save-energy-and-money/calculate-energy-use/calculate-appliance-operating-costsAustralian Government — YourHome
Validation and context reference for the importance of appliance energy-consumption labels and comparisons. Not a numerical input for results.
https://www.yourhome.gov.au/energy/appliances