About the Grade Calculator
This tool computes a weighted overall course grade the same way most instructors compute a final grade: by combining several categories — homework, tests, a final exam, or whatever your syllabus lists — where each category counts for a different share (weight) of the total. It reports the overall percentage, the letter grade, and the 4.0 GPA equivalent.
The formula
The weighted average formula used here is:
Overall grade (%) = ( score₁ × weight₁ + score₂ × weight₂ + score₃ × weight₃ ) ÷ ( weight₁ + weight₂ + weight₃ )
Each score is entered as a percentage (0–100), and each weight represents that category's share of the final grade, also as a percentage. If your homework is worth 20% of the grade and you scored 88%, tests are worth 30% at 82%, and the final exam is worth 50% at 90%, the overall grade is:
(88 × 20 + 82 × 30 + 90 × 50) ÷ (20 + 30 + 50) = (1760 + 2460 + 4500) ÷ 100 = 8720 ÷ 100 = 87.2%
Dividing by the total weight (rather than assuming it is always exactly 100) means the calculator still returns a mathematically correct weighted average even if your weights add up to something other than 100% — though for a standard course grade they normally should sum to 100%, and the "Total weight entered" result flags it when they do not.
Converting a percentage to a letter grade and GPA
The calculator maps the overall percentage to a letter grade and GPA point using the common United States plus/minus 4.0 scale:
- A+ / A: 93–100% → 4.0 GPA
- A−: 90–92.99% → 3.7 GPA
- B+: 87–89.99% → 3.3 GPA | B: 83–86.99% → 3.0 GPA | B−: 80–82.99% → 2.7 GPA
- C+: 77–79.99% → 2.3 GPA | C: 73–76.99% → 2.0 GPA | C−: 70–72.99% → 1.7 GPA
- D+: 67–69.99% → 1.3 GPA | D: 63–66.99% → 1.0 GPA | D−: 60–62.99% → 0.7 GPA
- F: below 60% → 0.0 GPA
This is one of the most widely used scales in US high schools and colleges, but it is a convention, not a universal law — some schools skip plus/minus grades entirely, some use a 10-point-per-letter scale instead of the narrower bands above, and some weight GPA differently for honors or AP courses. Always confirm the exact cutoffs on your syllabus or school handbook before treating the GPA shown here as official.
How to get the best results
- Use the exact category weights from your syllabus — they should add up to 100% for a normal course grade.
- Enter scores as percentages (0–100), not raw points; if you have points out of a total, divide first (e.g., 44 out of 50 is 88%).
- If your course has more or fewer than three categories, combine similar ones (e.g., add all quiz scores into one weighted "Tests" percentage) so the three fields represent your full grade.
- Double-check the "Total weight entered" result — if it is not 100%, your overall percentage is still correct math, but it may not match what your syllabus intends.
Practical context
This calculator performs the arithmetic your instructor's syllabus describes, but it cannot see extra-credit policies, dropped-lowest-score rules, curves, or late penalties that some courses apply after the weighted average is computed. Treat the result as your baseline grade before those adjustments, and check your school's official gradebook for the final number of record.