A crop sprayer used to deliver chemicals to agricultural crops in a field includes a chassis, a chemical storage tank mounted on chassis used to store fluid to be sprayed on the field, and apparatus for gauging an amount of fluid in the tank. The tank has two planes of symmetry perpendicular to one another forming a central axis created by the intersection of the planes of symmetry The apparatus includes a sight gauge, an inclinometer, and a multiplier scale. The inclinometer is mounted to the tank on a plane created by the sight gauge and the central axis of the tank created by the intersection of the planes of symmetry.
