📌 Overview

Calculate what any appliance costs to run per day, month and year from its wattage, hours of use and your electricity tariff.

💡 Electricity Cost Calculator

Calculate what any appliance costs to run per day, month and year from its wattage, hours of use and your electricity tariff.

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📖 Deep Dive: Electricity Cost Calculator

How the electricity bill is calculated

The basic unit is the kilowatt-hour (kWh, commonly called a degree). Formula: energy(kWh) = power(W) times hours used divided by 1000; cost = energy times price.

Power reference for common appliances

  • LED bulb: about 10W
  • Laptop: about 50W
  • Desktop plus monitor: about 200W
  • Rice cooker: about 800W
  • Air conditioner (1.5 HP): about 1100W
  • Water heater: about 2000W

    • An example

    An 1100W air conditioner running 8 hours a day at 0.6 per kWh: 8.8 kWh per day, about 5.28, about 158 a month, and about 475 over a whole summer (3 months).

    Practical ways to save

  • Each 1 C higher on the AC cuts consumption about 6%-8%.
  • Use a power strip to cut standby power completely.
  • Check the energy label: tier 1 is usually 20%-30% more efficient than tier 3.
  • In time-of-use areas, run laundry and charging in off-peak hours.