Energy Cost Calculatorv1.0.0

Enter each appliance or device you want to evaluate, specifying its power consumption in watts and the number of hours you run it per day. The calculator converts wattage into kilowatt-hours, multiplies by your electricity rate, and produces daily, monthly, and yearly cost estimates for every entry plus a combined total.

• Type the appliance name into the Appliance Name field (for example, "Window AC Unit" or "Desktop Computer").
• Enter the device wattage in the Wattage (W) field. Check the label on the device or its manual for the rated wattage. Fractions (such as 1/2), mixed numbers (such as 1 1/2), and decimals are all accepted.
• Enter how many hours per day the device runs in the Hours per Day field. Partial hours work (for example, 0.5 for 30 minutes).
• Click Add Appliance to add more rows. Each row tracks a separate device, and the totals update to reflect every entry.
• Open Settings to adjust the Electricity Rate ($/kWh) to match your utility bill. The default is $0.12 per kWh, which approximates the US national average. Also adjust Days per Month if your billing cycle differs from 30 days.
• Click Calculate to see a per-appliance breakdown showing daily kWh, monthly kWh, daily cost, and monthly cost, followed by combined monthly and yearly totals.
• Enable Show step-by-step formulas in Settings to see the conversion from watts to kilowatt-hours and the cost multiplication for each appliance.
• Click Reset to clear all appliances and restore default settings. All saved data in your browser is also cleared.
• The core formula is: kWh per day = Wattage / 1000 x Hours per Day. Daily cost = kWh per day x Rate. Monthly cost = Daily cost x Days per Month. Yearly cost = Monthly cost x 12.

Tracking electricity consumption at the appliance level reveals where most of your utility budget goes, making it straightforward to prioritize upgrades or adjust habits.

• Household budgeting: List every major appliance (refrigerator at 150 W running 24 hours, washing machine at 500 W running 1 hour, oven at 2000 W running 0.5 hours) to forecast the monthly electric bill and compare it against your budget target.
• Appliance comparison: Enter two versions of the same device (for example, an older 100 W incandescent bulb versus a 15 W LED replacement both running 8 hours a day) to see the annual savings from switching.
• Home office planning: Add a monitor at 30 W, a laptop at 65 W, a desk lamp at 10 W, and a router at 12 W, all running 10 hours per day, to estimate the incremental cost of working from home.
• Seasonal cost forecasting: Model summer cooling costs by entering a 1500 W portable air conditioner running 12 hours a day for a 30-day month, then compare against winter heating with a 1000 W space heater running 8 hours.
• Rental property management: Calculate baseline electricity costs for appliances included in a furnished rental (water heater, HVAC, refrigerator, microwave) to set a fair utility allowance for tenants.
• Solar offset analysis: Total your household consumption in kWh per month, then compare it against the expected output of a proposed solar panel system to determine what percentage of your bill the panels would cover.
• Small business operations: Add commercial equipment (a point-of-sale terminal at 50 W, display signage at 200 W, a commercial refrigerator at 400 W) to forecast monthly electricity overhead for a storefront.