Ever wondered how much it would cost to run your fan continiously for a certain period of time? Use this simple equation to find out. The fans wattage (W) is located on the specifications tab or spec sheet for each fan. You may also want to look at your electricity bill to find out how much you are being charged per kWh.

wattage x hours used ÷ 1000 x price per kWh = cost of electricity


Let’s take a look at the standard high speed 120 by 38 mm AC fan. According to the manufacturers spec sheet, it has wattage rating of 18 W. Let’s assume that you are being charged $0.14 per kWh, the average rate in the US. We take 18, multiply by 24, divide by 1000, and multiply by 0.14, to get a rate of $0.06 per 24 hour day. Multiply that by 30, and we're looking at a cost of around $1.80 per month to power this fan model continuously.