Says it's 1075. Though I'm willing to bet it's a bit longer. Anyone with eyes knows the target display for linear skillshots is off. Skills like Brands Sear, or Lux's light binding both extend slightly beyond the end of the pointer.
Also, when you say "out of range of my E", can you be more specific. Do you mean out of range of the centre of the orb, or the entire spell? Because at "max range", her E has a range of 1450. The 1100 range to the centre of the spell, and then the 350 "extra" range because of the AoE's radius from the centre. (I'll assume the former, because I highly doubt LiB has THAT big of a range).
Either way, it doesn't matter all that much. You'll be measuring if you'll hit a skillshot by eye in-game, not by the "actual" distance. Just learn and practice her different ranges and you'll be set.