Electricity Cost Calculator

Electricity calculation

Power

Quantity Hours per day Days per month

Advanced load setting

Average load

Use 100% for a continuously running load. Lower values can approximate cycling or inverter-driven equipment.

Electricity rate (optional) Currency

Energy used

kWh

Electricity rate

Fixed charge per day (optional) Billing days Currency

Result

Estimated monthly energy

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Core formula: kWh = kW × hoursCost = kWh × your electricity rate.

Known kWh: Cost = kWh × rateTwo-rate mode adds the two energy-cost parts and any optional fixed daily charge.

How the estimate works

Rated power is converted to kilowatts, adjusted by quantity and average load, then multiplied by operating time. The calculator does not use live tariff data.

Example: a 1500 W heater used 2 hours per day for 30 days.

1.5 kW × 2 h × 30 = 90 kWh/month

At 0.20 per kWh, the estimated monthly energy cost is 18.00.

Useful checks 4 × 100 W × 5 h/day × 30 days = 60 kWh/month2 kW × 3 h/day × 20 days × 50% load = 60 kWh250 kWh × 0.20/kWh = 50.00

What is the difference between kW and kWh?

kW is power. kWh is energy used over time. A 1 kW device running for 2 hours uses 2 kWh.

Why can real appliance use differ from the nameplate rating?

Thermostats, compressors and inverter controls may cycle or vary power. The optional average-load percentage can approximate this behavior when you have a reasonable estimate.

Does this calculator know my electricity tariff?

No. Enter your own rate from your bill or supplier. The calculator does not use live tariff or exchange-rate APIs.

Can I use a day/night tariff?

Yes. In Known kWh / Bill mode, choose Two-rate and enter the kWh and price for each rate separately.

Does the result include taxes or fees?

Only values you enter are included. A generic fixed daily charge can be added in bill mode, but country-specific taxes and tariff rules are not assumed.

Articles and explanations

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ELECTRICITY USE & COST

How to Calculate Electricity Usage and Cost Electricity use is straightforward to estimate when you know an appliance's power, operating time, and the price you pay per kWh. This guide explains watts, kilowatts, kilowatt-hours, the core formulas, worked appliance examples, and direct cost calculations when your kWh usage is already known. Power and energy use are different quantities Watts (W) and kilowatts (kW) describe power: the rate at which a device uses energy at a given moment. Kilowatt-hours (kWh) describe energy used over time. 1 kW = 1000 WEnergy, kWh = Power, kW × Time, hours A 1500 W appliance has a power rating of 1.5 kW. I..

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