Enter the appliance's power, its daily running hours, and the price per kWh (running days is pre-filled with 30 and can be edited), then click Calculate.
Equation Used
Monthly Consumption (kWh) = Power (W) ÷ 1000 × Running Hours per Day × Running Days per Month
Monthly Cost = Monthly Consumption (kWh) × Price per kWh
This formula is approximate because it assumes the appliance runs at its rated power for the entire running time, while some appliances (such as air conditioners and refrigerators) actually run at variable power depending on the load.
Worked Example
An air conditioner rated at 1500 W runs 8 hours a day for 30 days, with a price of 0.3 per kWh:
Consumption = 1500 ÷ 1000 × 8 × 30 = 360 kWh per month
Cost = 360 × 0.3 = 108 (your currency) per month
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