Anyone know the measurements for a fly leader with 20lb tippet? I prefer to tie my own leaders using leader material to save money, plus you get a slightly better cat out of it and it has less memory.

Longer tippet for flat calm days. Also depends on your size fly too. On windy days I like to keep my tippet shorter which makes it a bit stiffer. This will you from having wind knots and able to help roll over the fly. Depending on how I build my taper leader I usually use 12-24". When I used to be heavily in saltwater flyfishing I used to test my leaders at a lake to see how it unroll out. If you are planning to break any IGFA records I recommend you reading up on their rules what they required.