గణితం ఎలా పనిచేస్తుంది
The arithmetic is short and the tool shows every step. Kilowatt-hours per day is wattage ÷ 1,000 × hours used per day, and cost per day is that multiplied by your price per kWh. The longer periods are straight scalings of the daily figure: week × 7, month × 30.44 (the average month length across a year) and year × 365. The headline number is the monthly cost, with daily and annual shown beneath it and the full breakdown in the table.
Wattage and hours are the two things worth getting right. Twenty preset buttons fill the wattage field for you, spanning an electric water heater at 4,000 W, central AC at 3,500, a clothes dryer at 3,000, an electric oven at 2,400, a space heater at 1,500, a refrigerator at 150, a laptop at 50 and an LED bulb at 9. Hours accepts quarter-hour steps, and the currency select changes the symbol on the output only.
The model assumes the appliance draws its full nameplate wattage for every hour you enter, which is true of a heater or a kettle but wrong for anything that cycles. Fridges, freezers and air conditioners switch their compressor on and off, so a 150 W fridge plugged in for 24 hours does not use 3.6 kWh; enter an effective duty cycle, or measure with a plug-in watt meter. Standby draw, tiered tariffs and time-of-use rates are not modelled, and the currency picker does not convert your rate.
తరచుగా అడిగే ప్రశ్నలు
How much does it cost to run a 1500 W space heater? +
At three hours a day and $0.16 per kWh, that is 4.5 kWh daily, about $0.72 a day, $21.92 a month and $262.80 a year. Running it around the clock instead would be roughly eight times that, which is why heaters dominate winter bills.
Is the 150 W refrigerator preset right for a full 24 hours? +
No, and this is the most common mistake here. A fridge's compressor runs perhaps a third of the time, so entering 24 hours at 150 W overstates it badly. Enter around 8 effective hours instead, or use a plug-in meter to find your real daily kWh.
Why does the monthly figure use 30.44 days? +
Because 365 divided by 12 is 30.44, so it is the average calendar month rather than a rounded 30. Using 30 would understate your monthly cost by about 1.5 percent, which compounds noticeably on a high-draw appliance like a dryer or water heater.
Does changing the currency convert my electricity rate? +
No. The currency select only swaps the symbol shown on the results, between USD, EUR, GBP, AUD, NZD and CAD. Enter your own local price per kWh in the price field; nothing is converted between currencies at any exchange rate.
How do I cost something I only use a few times a week? +
Convert it to an average per day, since the hours field is per day and accepts quarter-hour steps. A dryer run for an hour three times a week is 3 divided by 7, or about 0.43 hours per day, which the field will take directly.
