How long is a piece of string 
Take half its length and double. This will give you its length.
Hi Flyloon,
I am guessing you are fairly new to fly fishing? If so, what I found when starting out with a similar outfit was that a tapered nylon leader was a great aid to fly turnover. I used one that tapered to 6lb breaking strain. To the end of this I tied about 18" of 5lb tippet. This gave a leader of about 10-11 feet which is about managable to start off with. Not too short but more importantly, not to long.
Hope that helps a little and please forgive my assumptions if I am wrong.
