This calculator requires the use of Javascript enabled and capable browsers. It is to determine the volume of a reservoir structure; the reservoir can actually contain water or potentially contain water, depending on the purpose. For the purposes of this calculator, a reservoir is a structure, pool, tank, basin, container, pond or lake, of regular or irregular shape, to hold water, for a specific purpose. This calculator does not approach the construction methods of the reservoir, only the volume requirements. There are basic environmental concerns as possibilities, however, this calculator's purpose is to provide an approximate volume as needed. In this calculator, the reservoir is assumed to be irregular but it could be the surface shape of a square, a rectangle, a circle (or percentage thereof) , a triangle, all with depth (examples might be a cube, cylinder, rectangular prism or triangular prism, or an irregular shaped of those combinations), volume capable, structure. If it is a square or rectangle surface shape, enter the depth, length and width dimensions in the Rectangle section only. If it is an irregular reservoir, segment it into the surface shape of a rectangle and up to four triangles. If it is a cylinder, enter the radius or 1/2 of the diameter; also enter the percentage of the cylinder used. (As an example, if the circular surface is a semi-circle, put in 50 as the percentage. If it is a full circle, leave the default of 100 percent.) They do NOT need to be right triangles. Enter the consistent or average depth used in all the calculations. Enter the height and base of all of the triangles in each Triangle section required (up to 4), and length and width dimensions in the Rectangle section. If you only have one triangle and a rectangle, only use those fields. In triangles, the height is measured in a perpendicular from the highest point to the base. Any combination can be used and the potential of the shapes possible is almost limitless. The depth is from the surface of the structure to the flooring and is consistent in all calculations; if this is not a universal depth, take an average. All entries should be numeric. The answers are returned as cubic unit numbers, based on your entries. Enjoy!

In the second calculator, assuming that your entry values were in feet, the number of surface acres is returned, along with the number of acre-feet and acre-inches of water volume, based on the entered depth. Both are units used to measure volumes of water, typically for use in irrigation. One acre-foot is the volume of water sufficient to cover an acre of land to a depth of 1 foot, is equal to 43,560 cubic feet, approximately 325,851 U.S. gallons (approximately 1233.48 cubic meters). At year 2000 considering American rates of consumption, on average 1 acre-foot of water is enough to meet the industrial and municipal demands of 4 people for a year. An acre-inch, the volume of water needed to cover an acre to a depth of 1 inch, 1/12th of an acre-foot, is approximately 27,154.25 gallons or approximately 102.79 cubic meters.