How this tool works
Energy use = watts / 1000 x hours x days. Cost = kWh x price per kWh.
Home and Bills
Electricity Cost Calculator
Turn watts, hours and your electricity rate into an estimated running cost for a device.
What to do with the answer
Turn watts, hours and your electricity rate into an estimated running cost for a device. The useful part is not just the first answer; it is checking whether the answer still makes sense when the uncertain number changes.
Quick check
- Read the result label first so you know whether it is monthly, yearly, daily, a percentage, a date or a total.
- Change the input you are least sure about and compare the second answer with the first.
- Use a related guide or worksheet when the result affects a bill, budget, health target, study plan or purchase.
Check the label before trusting the cost
Electricity estimates are only as good as the wattage and price used. If a device has several modes, such as standby, eco, low, medium or high, run the calculation for the mode you actually use most often. Always-on devices deserve extra attention because small wattage can still add up over many hours.
Use the result in the planner
Run the calculation for one real device, then write the answer into the Home Energy Audit Planner beside the room and appliance name. If the result is surprising, change the hours or electricity rate and calculate again before deciding what to do.
The clearest next step is usually one small action: measure the device properly, use it for less time, add a timer, move it to a cheaper routine or leave it alone because the cost is not worth worrying about.
Check the inputs first
Electricity cost estimates depend on watts, hours, days and price per kWh. Use the number on the appliance label, manual, bill or smart plug where possible. If you are guessing, mark the planner row as low confidence.
For always-on devices, time can matter more than the wattage looks at first. For high-power devices, even short use can matter. The planner helps you compare both without trying to remember everything in your head.
When this estimate helps
This page is useful when you have one device and a rough idea of how long it runs. A heater used for two hours, a dehumidifier left on overnight, a gaming setup used after school or a home office monitor running all day can all be checked with the same inputs.
Write the answer beside the device in the Home Energy Audit Planner, then compare it with another device from a different room. That comparison is more useful than one isolated cost because it shows where your attention is worth spending. If the estimate is low, you can leave the device alone and move on. If it is high, check the wattage or hours again before choosing an action.