What is the cost to run a normal 40 watt fluorescent light for 24 hours?

Question

4 foot fluorescent bulb

Answer 1

Let's say you pay $0.13/kilowatt-hr:

(40 W)X24 Hr = 960 Watt-hour = 0.960 Kilowatt hours (over the 24-hr period)

0.960 KWHr X $0.13/KWHr =  about 12.5 cents per day.

Answer 2

That is 960 Wh or nearly 1 kWh. The going rate for electricity varies, but that would usually be a couple cents. You can see the cost per kWh on your bill.