Electricity Cost Calculator

How to calculate electricity cost

1. Choose Power and time if you know electrical input power and usage time. Choose Energy in kWh if you already have the energy amount.
2. Enter the figures and select the matching units. Power uses W or kW; time uses hours or minutes.
3. Select a currency and enter your own price per kWh in whole currency units. For a repeated daily estimate, open Repeat daily and enter the number of days.
4. Read the estimated energy cost. Open Calculation details to check the inputs and formula, or copy the current result.

A clear estimate without a tariff dashboard

• Calculate from electrical input power and time, or directly from known kWh.
• Use watts or kilowatts, and hours or minutes, with an explicit price per kWh.
• Optionally repeat the same daily usage over an entered number of days.
• Keep fractional electricity prices, even for currencies displayed without decimal places.
• See qualified rounded and tiny positive results rather than mistaking a small charge for zero.

When this calculator helps

• Estimate the energy charge for lights, a computer or another device with known average input power and operating time.
• Price a measured or estimated kWh amount for a chosen period without entering appliance details.
• Estimate the energy portion of EV charging from billed or meter-side kWh and the matching per-kWh price.

Use the right power, energy and price

Power is the rate of energy use. W and kW describe power; kWh describes energy. A kW value is not an energy reading.

Use average electrical input power for the entered time. A maximum rating may not represent actual use, especially when equipment cycles or changes its operating level. Heat output is not electrical input power.

Use a per-kWh price in the selected currency. EUR 0.20 means 20 cents per kWh, not EUR 20. The tool does not infer a rate from your language or location.

With Repeat daily off, time is total usage. With it on, the same number becomes time per day and is multiplied by your entered day count. Months and years are not assumed.

Known energy mode prices the kWh you supply. For EV charging, battery capacity or a charge percentage is not automatically billed energy. Losses already present in a meter reading remain present; no loss factor is added or removed.

Energy and cost are calculated before display rounding. The final money figure follows the chosen currency's decimal precision, not cash-payment rounding or a supplier's billing rule.

Worked electricity cost examples

A device drawing 1,500 W for 2 hours uses 3 kWh. At EUR 0.25 per kWh, its estimated energy cost is EUR 0.75.

1,200 W for 30 minutes uses 0.6 kWh. At EUR 0.20 per kWh, the energy charge is EUR 0.12.

9 W for 5 hours per day over 30 days uses 1.35 kWh. At EUR 0.28 per kWh, the unrounded cost is EUR 0.378, displayed as about EUR 0.38.

40 billed kWh for EV charging at EUR 0.20 per kWh gives EUR 8.00 for energy. Session, parking and other fees are not added.

1,152 kWh at EUR 0.1387 per kWh gives EUR 159.7824 before rounding, displayed as about EUR 159.78. Rounded daily costs are not multiplied to obtain this total.

What the estimate does not include

This is an entered-rate energy estimate, not a complete electricity bill. No standing, demand, session or other fixed charges, tax calculation, tier or time-of-use tariff is added.

Changing prices or power levels need appropriate measured energy or a matching average assumption. The tool does not infer duty cycles, recommended wattages or current local tariffs.

Currency changes reinterpret the retained price; they do not convert it. Values are rounded for display using the selected currency's minor-unit precision.

The result does not determine wiring safety, electrical capacity, battery health, charging time, emissions or guaranteed savings.

Your calculation inputs

Inputs stay in page memory. The tool adds no account, upload, saved history or share link containing your figures. Copy is performed only when requested.

The surrounding website can make normal requests under its existing consent and analytics settings. Local arithmetic is not whole-site privacy certification.