Calculating your electricity usage is crucial for managing your energy consumption and costs.
This calculator helps you estimate how much energy (in kilowatt-hours, kWh) a specific
appliance or device consumes over a month, based on its power rating and how often it's used.
How it Works
The fundamental unit of electrical energy is the kilowatt-hour (kWh). One kilowatt-hour
represents the energy consumed by a 1,000-watt device running for one hour. Our calculator
takes the power of your device, the duration it's used, and the frequency of its use to
compute its total monthly consumption.
Step 1: Calculate Daily Watt-Hours (Wh)
Daily Wh = Device Power (Watts) × Hours Used Per Day
Step 2: Calculate Weekly Watt-Hours (Wh)
Weekly Wh = Daily Wh × Days Used Per Week
Step 3: Calculate Monthly Watt-Hours (Wh)
Monthly Wh = Weekly Wh × Weeks Used Per Month
Budgeting: Estimate your electricity bills more accurately.
Energy Efficiency: Identify high-consumption devices and consider alternatives or reducing usage.
Appliance Comparison: Understand the energy impact of different devices.
Environmental Awareness: Make informed decisions to reduce your carbon footprint.
Tips for Accurate Measurement:
Device Power: Look for the wattage (W) on the device's label or in its manual. If it only lists voltage (V) and amperage (A), multiply them to get watts (W = V × A).
Usage Time: Be as precise as possible with daily usage hours.
Frequency: Accurately count the days per week and weeks per month the device is actively used.
Multiple Devices: To calculate total household usage, use the calculator for each major appliance and sum the results.
function calculateElectricityUsage() {
var devicePower = parseFloat(document.getElementById("devicePower").value);
var hoursPerDay = parseFloat(document.getElementById("hoursPerDay").value);
var daysPerWeek = parseFloat(document.getElementById("daysPerWeek").value);
var weeksPerMonth = parseFloat(document.getElementById("weeksPerMonth").value);
var resultDiv = document.getElementById("result");
// Input validation
if (isNaN(devicePower) || devicePower < 0 ||
isNaN(hoursPerDay) || hoursPerDay < 0 ||
isNaN(daysPerWeek) || daysPerWeek 7 ||
isNaN(weeksPerMonth) || weeksPerMonth < 0) {
resultDiv.textContent = "Please enter valid positive numbers for all fields.";
resultDiv.style.backgroundColor = "#dc3545"; // Red for error
return;
}
// Calculation
var dailyWattHours = devicePower * hoursPerDay;
var weeklyWattHours = dailyWattHours * daysPerWeek;
var monthlyWattHours = weeklyWattHours * weeksPerMonth;
var monthlyKiloWattHours = monthlyWattHours / 1000;
// Display result
resultDiv.textContent = "Estimated Monthly Usage: " + monthlyKiloWattHours.toFixed(2) + " kWh";
resultDiv.style.backgroundColor = "#28a745"; // Green for success
}