Exam Grade Calculations: Understanding How Points Become Letters

You scored 47 out of 55 on the midterm. Is that a B or a B+? What grade do you need on the final to get an A in the course? How much does the final exam actually matter given your current average? These calculations are straightforward but students get them wrong constantly because they mix up weighted vs unweighted averages. Understanding the math eliminates grade anxiety and enables strategic studying. Percentage to letter grade The standard US scale (with common variations): Percentage Letter GPA 93-100% A 4.0 90-92% A- 3.7 87-89% B+ 3.3 83-86% B 3.0 80-82% B- 2.7 77-79% C+ 2.3 73-76% C 2.0 70-72% C- 1.7 67-69% D+ 1.3 60-66% D 1.0 Below 60% F 0.0 Your score: 47/55 = 85.5% = B But this is where it gets interesting: what letter grade this actually gets in the course depends on the weighting. Weighted averages Most courses weight different assessments differently. A typical structure: Homework: 20% Midterm: 25% Project: 20% Final exam: 35% Your current grades: Homework: 92% Midterm: 85