Last year, Ryan Carson, founder of Carsonified, shared his knowledge about calculating web apps and introduced the community to 6 key metrics for web apps. In addition to that, he shared a spreadsheet document on Google Docs, which was extremely helpful for a lot of founders to calculate their startups.

Half a year later, Marc Gayle, founder of CompVersions.com, had taken this document a step further and added some nice features like Variable Hosting Costs (AWS / Cloud), Fixed Hosting Costs, Gross Profit and reorganized the document.
A great start for every expectant founder!