Test grades
How Many Questions Can You Miss and Still Pass?
Learn how to calculate the maximum questions you can miss and still earn a passing grade, with examples for 10-, 20-, 25-, 50-, and 100-question tests.
GRADING KNOWLEDGE BASE
Grade Calculator Blog
Clear, practical guides for understanding test grades, raw scores, weighted categories, extra credit, rounding rules, and percentage-to-letter-grade conversions.
4 in-depth guides · Teacher and student friendly · Updated July 16, 2026
LATEST GUIDES
Understand the math behind every grade.
Each guide answers one grading question directly, shows the formula or policy behind it, and links to the right calculator for the next step.
Grade formulas
Weighted vs. Unweighted Grades: What Is the Difference?
Understand weighted and unweighted grades, calculate weighted category averages, and see how course weights differ from weighted GPA.
Extra credit
How Extra Credit Affects Your Grade
Learn how bonus points and extra-credit assignments change a test or course grade, with formulas, examples, and common gradebook methods.
Grade policies
Grade Rounding Rules: When Does 89.5 Become 90?
Understand common grade rounding methods, decimal precision, boundary scores, and why an 89.5% does not automatically become a 90% in every course.