Default [Q] Nandroid backup

im wanting to do a full nandroid back up as ive just rooted ny LG-D802, but i have a concern.

Im assuming that the backup file created is pretty big in size.
Approximately how big?

As i have the D802 i have no SD slot, so memory runs out pretty fast!

I currently have around 3GB of free space, and could potentiall free up another 1 or 2 gb by removing all my music and photos / videos?

Am i going to be able to complete a full back up?
Or will i run out of space?