Overview and getting-started instructions are available in the PDF. Download it from this link: https://github.com/nickvzorn/spreading-sheet/raw/master/Personal_Financial_Forecasting_Model_HowTo.pdf
This GitHub repository hosts a spreadsheet that can be used to forecast people's financial lives from "now" through retirement and until death. It offers simple user parameters for almost every imaginable type of account and debt that one person (or a couple) could have (e.g. mortgage, savings, 401(k), IRAs, social security, pensions, investments, expenses, credit card debt, childcare, 529-type accounts and subsequent college costs, etc.), and it allows the user to enter their own assumptions about how these things will grow/change. The workbook plots the impact of those assumptions on their monthly income, net worth, accumulated debt and savings for college.
There are a fair number (130+) of input parameters, but they're pretty intuitive or easy to look up on your various account statements. There's also a README tab in the front that summarizes the model assumptions.
Three versions are currently provided - Excel 2013, Excel 2003, and LibreOffice. Click on the one you want, then click the "Download" button on the next page.
This workbook was created in LibreOffice Calc (https://www.libreoffice.org/download), which is free software similar to Microsoft Excel.
Originator: Nick V. Zorn (email nickvzorn at gmail dot com)
Date project began: 06 May 2017
Date last modified: 10 August 2017