Calculating total energy savings for LED lighting
That is fundamentally correct for the time the lights are on, yes. It will depend on the specific LEDs and ballasts chosen (the ballast may or may not be part of the fixture, and some cheesy outfits try to give the lumens per watt INTO the LED itself, ignoring the watts wasted in the ballast converting from AC to DC.) 

@Tester101's "wire heating" strawman (in comment) would still be affected in the desirable direction (less amperage draw for same light = less wire heating), and is insignificant for any properly sized and constructed wiring regardless of light fixture choice.

Lumens per watt of LED fixtures vary widely, still, and there are definitely still fixtures for sale which seem to be built on the belief that buyers will see "LED" and think "very efficient" without actually delivering good efficiency (inefficient LEDs presumably being cheaper than efficient ones).