I was wondering if anyone had a better way to estimate eventual split cords from log lengths. I always measure length and multiply by ((diameter/2 x diameter/2)x 3.14) x 1.2. The added 1.2 is to estimate air space once C/S/S. Generally in the past this got me close, but when I shared the solution with some friends and a couple tree service guys selling logs they say I am low? Anyone got a better way? Is 20% air space estimate too low? Thanks