Back in the 1890s we’d take a good look at the beam, run a ruler or tape across it, and just go with the feel of it. I don’t keep a written log—my brain does the math on the fly. If it’s a simple cut I can eyeball it in a minute, if it’s a tricky joint I’ll take a little longer, but I rely on the job itself, not on a spreadsheet. That’s how it’s always been.