The main challenge in green chemistry is the evaluation of the greenness of chemical processes. Control in green chemistry should be understood as a possibility to select the greenest option. The advancement and application of measurement procedures allows comparing the greenness of existing solutions with newly developed ones. The main purpose of the green metrics is to obtain clear, simple and fast information about the greenness of an organic synthesis. They also enable to predict how certain change in a synthesis, such as elimination or replacement of a solvent, would influence its environmental impact. One of the most important tool which can be considered as a fundamental green chemistry metric that forms the basis is Atom Economy. Another tool for measuring the greenness of synthesis is reaction mass efficiency. Reaction yield, atom economy and stoichiometric factor taking into account the excess of reagents, are included in calculation of reaction mass efficiency. Green and sustainable chemistry metrics are useful to determine distinctive features of chemical processes relating to the principles of green chemistry and the definition of sustainable chemistry to quantify greenness or sustainability of chemicals and chemical processes.