Cant remeber the precise figure but its around the 2 litre mark. So if you have a 5 litre can, you will have enough. Fill to the full mark, run the engine, check the level and top up.
<hr width=100% size=1>this post is a personal opinion, and you should not base your actions on it.
Be wary of overfilling the engine oil on a diesel - its possible for the oil to be picked up by the piston and carried to the cylinder...the engine will then "run away".