Choose the calculator by the record you have
Start with a final-grade or weighted-grade calculator when the source is a course gradebook and syllabus. Use GPA tools only when you have course credits, completed course grades, and the grade-point scale published by your institution. Attendance tools need official attended and held-class counts, while deadline tools need a dated notice and the rule that defines calendar, school, working, or class days.
Keep inputs from different academic layers separate. An exam weight is not a course credit, a grade-so-far is not always the final weighted percentage, and an excused absence request is not an approved attendance count. When a value is pending, calculate a conservative scenario and a clearly labeled approved scenario instead of silently choosing the favorable one.