yes and no each lighting type is different. LEDs use alot less power.
a general rule of thumb is MH cover a 24"x24" area for an aquarium that is 24" deep a 250watt should be used, for 30" deep 400watts. where as with T5HOs individually reflected should be one lamp per 3-5" of front to back.
LEDs are anotehr ball game all together as there are different types with different reflectors and different wattages, but generally use about 33% of the power MH do