How many watts of led equals 40 watts of fluorescent?

Watts are a unit of power. So 40 watts of power to an LED are the same as 40 watts of power to a fluorescent. Sometimes LEDs are rated in equivalent watts which is an attempt to relate watts to brightness or lumens. You need to compare lumens and the "temperature" of the bulbs in Kelvin to get the comparison I think you are looking for.