Our tutorial, written in Excel 2010, is designed to familiarize users with a commonly used approach in species-distribution modeling—the maximum-entropy approach. Users step through the worksheets and learn about the mathematics and assumptions used, fitting the model using the Microsoft Solver Add-in. Text in the tutorial refers to a publicly available, non-Microsoft software tool called MaxEnt, available at http://www.cs.princeton.edu/~schapire/maxent/. Users can save the data used in the Excel tutorial and use it in the MaxEnt software package.