Kwh Calculator

Results

Total Energy Consumption: 0 kWh

Estimated Total Cost: $0.00

Calculation based on (Watts × Hours × Days) / 1000.

How to Use the kWh Calculator

Understanding your electricity bill starts with knowing how many kilowatt-hours (kWh) your appliances consume. This calculator helps you translate technical wattage ratings into real-world monetary costs.

The kWh Formula

To find the kWh used by any appliance, you use the following formula:

(Watts × Hours per Day × Number of Days) / 1,000 = Total kWh

Practical Example

If you have a 1,500W space heater running for 4 hours a day for a full 30-day month:

• Calculation: (1,500W × 4h × 30d) = 180,000 Watt-hours
• Convert to kWh: 180,000 / 1,000 = 180 kWh
• Cost: If your rate is $0.15/kWh, the cost is 180 × $0.15 = $27.00.

Where to Find Wattage Info?

Most appliances have a "nameplate" on the back or bottom indicating their power rating. If it only lists Amps and Volts, you can calculate Watts by multiplying them: Watts = Amps × Volts.

function calculateEnergyUsage() { var watts = parseFloat(document.getElementById("deviceWatts").value); var hours = parseFloat(document.getElementById("hoursPerDay").value); var days = parseFloat(document.getElementById("daysCount").value); var rate = parseFloat(document.getElementById("costPerKWh").value); if (isNaN(watts) || isNaN(hours) || isNaN(days) || watts <= 0 || hours < 0 || days = 0) { totalCost = totalKwh * rate; } document.getElementById("totalKwhResult").innerText = totalKwh.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2}); document.getElementById("totalCostResult").innerText = "$" + totalCost.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2}); document.getElementById("usageResult").style.display = "block"; }