The calculation is intended for the purposes of geometric and strength designs of spiral cylindrical torsion springs made of wires and rods in circular sections, cold formed, loaded with a static or cyclic loading. Application is developed in MS Excel, is multi-language and supports Imperial and Metric units and solves the following main tasks: - Automatic design of the spring. - Selection of the optimal design of the spring with respect to strength, geometry and weight. - Static and dynamic strength tests. - Support for Cold formed springs and Hot formed springs - Calculation of the working forces of a spring with known production and mounting dimensions. - Calculation of mounting dimensions for known spring loading and production parameters. - The application includes a table of commonly used spring materials according to ISO, ASTM/SAE, DIN, BS, JIS and others. - Support of 2D CAD (AutoCAD, AutoCAD LT, IntelliCAD, Ashlar Graphite, TurboCAD) and 3D CAD in full calculation package (Autodesk Inventor, SolidWorks). The calculation is based on data, procedures and algorithms from specialized literature and the standards EN 13906-2, and DIN 2088.This module is a part of MITCalc - Mechanical and Technical Calculation Package for gear, belt and chain drives, springs, beam, shaft, bolt connection, shaft connection, tolerances and many others.