Pipe and Tank Volume Calculator

Volume is one of those numbers a trade needs on the spot and almost never has written down. How much water sits in that run before you cut it. What the tank in the crawlspace actually holds. What you are draining, filling, dosing or hauling away. This works it out from measurements you can take with a tape and reports the same volume five ways, so you can hand it to a supplier, a client or an inspector without converting anything in your head.

Two inputs carry nearly all the weight. The first is inner diameter: the bore, not the outside of the pipe. Volume rises with the square of the radius, so measuring over the wall of a thick pipe overstates what it holds by more than most people expect, and it is the most common way this number comes out wrong. The second is the unit you measured in. Pick it before you type, because a tank entered in inches and read as feet is out by an amount nobody notices until the truck is on site.

A round tank lying on its side is the awkward one. It does not fill evenly. Near the middle, an extra bit of depth adds far more volume than the same depth near the bottom or the top, so a dipstick reading is never a straight percentage of capacity. That is what the partial-fill mode is for: give it the depth and it gives you both the volume and how full the tank really is. Take the measurement once, write it down against the address, and nobody has to crawl back under the house to get it again. Zeus keeps notes and measurements with the job record for that property, so a number like this stays with the work.