Pachan Dhanji Patel could take a girth, a length and a count and give you the answer before you had finished writing it down. Calculators failed against him.
He never needed one of these. We built it for the rest of us, and for every carpenter, contractor and dealer on this road who does this arithmetic a dozen times a day on the back of a bill book. Use it, free, whether or not you ever buy a foot of timber from us.
Quarter girth is the girth divided by four. Hoppus cubic feet is that quarter girth squared, times the length in feet, divided by 144. Hoppus sits about 21.5% below true cylindrical volume, and that gap is the allowance for the slabs sawn off to square the log. It is the standard measure for round timber and it is what your supplier is quoting.
Benin, Burma, Colombian and Nigerian teak, and Gabon padauk, sawn to your cutting list in Madhavaram. Teak doors and frames made in house. Saw millers since 1989.