The VOFTools library includes efficient analytical and geometrical routines for (1) area/volume computation, (2) truncation operations that typically arise in VOF (volume of fluid) methods, (3) area/volume conservation enforcement (VCE) in PLIC (piecewise linear interface calculation) reconstruction and(4) computation of the distance from a given point to the reconstructed interface. The computation of a polyhedron volume uses an efficient formula based on a quadrilateral decomposition and a 2D projection of each polyhedron face. The analytical VCE method is based on coupling an interpolation procedure to bracket the solution with an improved final calculation step based on the above volume computation formula. Although the library was originally created to help develop highly accurate advection and reconstruction schemes in the context of VOF methods, it may have more general applications. To assess the performance of the supplied routines, different tests, which are provided in FORTRAN and C, were implemented for several 2D and 3D geometries. Program summaryProgram Title:VOFToolsProgram Files doi:http://dx.doi.org/10.17632/brrgt645bh.1Licensing provisions: GNU General Public License, version 3Programming language:FORTRAN and C, with C interfacesNature of problem: The package of routines includes simple and efficient analytical and geometrical tools for area/volume computation, truncation operations that typically arise in VOF (volume of fluid) methods, area/volume conservation enforcement (VCE) in PLIC (piecewise linear interface calculation) reconstruction and computation of the distance from a given point to the reconstructed interface.Solution method: The volume (area in 2D) computation of a polyhedron (polygon in 2D) uses an efficient formula based on a quadrilateral decomposition and a 2D projection of each polyhedron face. The analytical VCE method is based on coupling an interpolation bracketing procedure with an improved final calculation step based on the above volume computation formula. Also, the exact distance from a given point to a reconstructed polygonal interface is calculated.Restrictions: Convex 2D and 3D polytopes.