I've taken our Quarter system and made a spreadsheet for the year. It has school holidays added which can be changed easily. There is one page that is an example page that shows comments with a sample student and how to use the spreadsheet. This is a simple "average the grades" spreadsheet. Different categories count more (quizzes count 2x while tests count 4x). The semesters are cummulative for our district but can be easily changed :) Enjoy!