We thought you'd never ask. The descriptions below will help you come up with the numbers to plug in. To get back to the calculator just close this window. The calculator window is behind it. Most people use acid brushes, which are cheap but wear out quickly.
People also use the little pump jars which quickly become dirty and clog up with flux.
Contact your tool crib people or your purchasing people to estimate how much you are spending on these supplies in one year. Divide that by the number of your techs to determine your annual tool cost per workbench. This varies widely by the type of boards being cleaned, the fluxes and solvents being used, and the quality of their supervision. Compare their estimates to your purchasing data on solvent purchases. However you get to it, ultimately put your best estimate of the pounds of solvent used per day per tech.