Here you can download the manual

(or place this link in your browser:!AjVUSe5Oqe7pgT1Ufh20OEdHJslN?e=huTlKI )


Here you can download the Add-In as a zipped file

(or place this link in your browser:!AjVUSe5Oqe7pgSqZoQpcAN8Eo3Tn?e=xq483Q  )

Download this file to a folder of your choice and unpack it. If your Antivirus software detects the file "Stoichiometry.exe" as malicious, please read this. After unpacking, double click the file "Stoichiometry"- it is an exe file and does not need installation. See the manual for more info.

If you have problems downloading the file, i can send it to you by email or a WeTransfer link.


In order to put pictures of molecules on an Excel worksheet, also OpenBabel needs to be installed on your PC. See the manual for more info; you can download OpenBabel in the Links page.


This addin is free to use for everyone.

If you like this software and use it regularly, you can donate to support and sponsor further development. As a sponsor you will get a personal license key via email, you will be informed of updates of the software and the support messages will not appear anymore.

More info on how to support this project is provided for in the support messages of the application.


Version history:

Jan. 09, 2017          v2.21

                                Bug fix (drawing of smiles string in Excel 64-bit)


Dec. 18, 2016         v2.20

                                 Support for Excel 2016.


Dec. 23, 2014        v2.10

                                 addition of a Periodic Table in the menu and functions related to the



Mar. 8, 2014           v2.01

                                 change in security settings to avoid startup errors on some systems.


Feb. 12, 2014         v2.01

                                 Support for Excel 2013. Adaptations in datafile & improvements.

                                 This version is only compatible with Excel 2007, 2010 and 2013!


June 24, 2013        v1.60

                                  New functions for mass spectroscopy. Some bug fixes and



May 26, 2013        v1.52

                                  Bug fix (calculations with iodium in Composition and Reactions)


Mar 23, 2013            v1.52

                                   Fix for use of the add-in in Excel 2003/2007.


Jan 31, 2013             v1.51

                                    Fix for broken links to Stoichiometry functions in user- created



Jan 26, 2013             v1.50

                                    Possibility to save reactions;

                                    Drawing of (organic) molecules from SMILES strings;

                                    Improvements in backup/restore and Settings;

                                    Changes in the menu structure.


Oct 5, 2012                v1.40

                                    Improvements in fraction calculations;

                                    Improvements in calculations with isotopes;

                                    New worksheet function;

                                    Bug fixes.


Sep 1, 2012               v1.31

                                     Elements 104-118 and their isotopes added;

                                     Improvements for calculations with isotopes; possibility for

                                     automatic choice of most abundant isotope;

                                     Several bug fixes;

                                     Extra option for weight calculations.


July 7, 2012                V0.31

                                      Bug fix in saving of isotope weights.


July 2, 2012                 V0.30

                                      A menu ribbon for Excel 2007/2010 is added;

                                      Improvements for calculations with isotopes;

                                      Backup and Restore function for abbreviations;

                                      Some bug fixes


May 31, 2011              V0.20

                                      Some improvements, including starting in an open Excel window.

                                       This makes it possible to use the add-in in combination with other

                                      add-ins and workbooks.


Nov 20, 2010              Fix for non-english language version of Excel


 Oct 10, 2010              V0.10