Electricity Cost Single Usage Calculator
Find out exactly what it costs each time you switch on an appliance. Enter the wattage, how long one use lasts, and your electricity rate — then see the per-use cost alongside weekly, monthly and annual projections.
W
minutes
per kWh
times
Electricity cost for one complete use of the appliance
- 1
Power in kilowatts
1,000 ÷ 1 000 = 1 - 2
Duration in hours
30 ÷ 60 = 0.5 - 3
Energy per use
1 × 0.5 = 0.5Kilowatt-hours consumed in a single use. - 4
Cost per use
0.5 × 0.15 = 0.0750
How does this calculator work?
Divide wattage by 1,000 and minutes by 60 to get kWh per use; multiply by your per-kWh rate. A 1,000 W appliance running 30 minutes at $0.15/kWh consumes 0.5 kWh and costs $0.075 per use — about $27 per year if used daily.
Formula
How this is calculated
Every electrical device converts power into energy over time. Power is measured in watts (W) — the rate of energy use. Energy is what you actually pay for, measured in kilowatt-hours (kWh): one kWh equals a 1,000-watt device running for one hour, or a 100-watt bulb for ten hours. Converting the wattage to kilowatts (÷ 1000) and the duration to hours (÷ 60), then multiplying together, gives the kWh consumed in a single use. Multiplying by your per-kWh tariff gives the cost per use.
The per-use cost is often a few cents, but it compounds across many uses. The calculator projects weekly cost (cost per use × weekly uses), monthly cost (weekly × 365.25 ÷ 12 ÷ 7 ≈ 4.35 weeks) and annual cost (weekly × 52), making it easy to spot which appliances dominate your bill.
This calculator assumes the appliance draws its rated wattage for the full duration — a reasonable assumption for resistive loads (kettles, toasters, electric heaters). Devices with thermostats, compressors or variable-speed motors cycle on and off, so treat the result as an upper estimate for those. Fixed supply charges, taxes and tiered tariffs are excluded; use your average blended per-kWh rate from your bill for the closest figure.
Frequently asked questions
Check the rating label on the back or base of the device, the plug, or the manual. If only amps and volts are listed, multiply them: watts = volts × amps. For variable-power devices (e.g. a dimmer-controlled lamp), use the average or typical setting.
Look on your utility bill — it is usually listed as cents or pence per kWh. Rates vary widely (typically $0.10–$0.35/kWh in most countries). If you are on a time-of-use tariff, enter the peak or off-peak rate for the time the appliance runs. The bill's 'energy charge' line item is the right figure to use.
Most individual uses consume a fraction of a kWh, making the per-use cost only cents. The impact accumulates over many uses: a 1,000 W appliance running 30 minutes daily at $0.15/kWh costs about $27 per year. High-draw appliances like electric ovens or tumble dryers, used for longer durations, show the largest single-use costs.
TG we-Calculate Editorial Team. (2026). Electricity Cost Single Usage Calculator [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/electricity-cost-single-usage-calculator
TG we-Calculate Editorial Team. "Electricity Cost Single Usage Calculator." TG we-Calculate. 2026. https://we-calculate.com/calculator/electricity-cost-single-usage-calculator.
TG we-Calculate Editorial Team, "Electricity Cost Single Usage Calculator," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/electricity-cost-single-usage-calculator
@misc{wecalculate_electricity_cost_single_usage_calculator, title = {Electricity Cost Single Usage Calculator}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/electricity-cost-single-usage-calculator}}, year = {2026}, note = {TG we-Calculate} }
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