How a semester grade is calculated
A semester grade is a weighted average of the two quarter (or term) grades and the semester exam. Each part is multiplied by its weight, and the three products are added. The weights come from your school or district grading policy, and they always add up to 100%.
semester grade = Q1 × w1 + Q2 × w2 + exam × w3w1 + w2 + w3 = 100%. Write the weights as decimals: 40% → 0.40.
Worked example
Quarter 1: 88%. Quarter 2: 84%. Semester exam: 79%. Weights 40% / 40% / 20%.
88 × 0.40 = 35.2. 84 × 0.40 = 33.6. 79 × 0.20 = 15.8. Total: 84.6%, a B on a plus/minus scale.[1]
Before the exam, the calculator works backwards. Leave the exam box blank and it shows the exam score needed for an A, B, C or D for the semester. With 88% and 84%, the quarters average 86%, so the exam needs 56% for a B, while an A (90%) would take 106% and is out of reach.
Semester grade calculator for high school weightings
High schools and districts set their own split, so the same report card can produce different semester grades. In the examples below the exam counts anywhere from 0% to 25%; with no exam, the two quarters are simply averaged. South Carolina’s statewide policy, for example, sets how final exams and grade points work in public high schools across the state.[2] Use the chips in the calculator for common splits, or type your school’s numbers.
| Split (Q1 / Q2 / exam) | Semester grade | Letter |
|---|---|---|
| 40 / 40 / 20 | 82% | B− |
| 45 / 45 / 10 | 83.5% | B |
| 37.5 / 37.5 / 25 | 81.25% | B− |
| 42.5 / 42.5 / 15 | 82.75% | B− |
| 50 / 50 / 0 | 85% | B |
The heavier the exam, the more a weak exam pulls the grade down: with these scores the semester grade falls from 85% with no exam to 81.25% when the exam counts 25%. If your exam is your strongest piece, the reverse happens.
Final semester grade: when the report card shows letters
Some schools record quarter grades as letters and average their grade points instead of percents. In that case, convert each letter to points (A = 4, B = 3, C = 2, D = 1, F = 0), apply the same weights, and convert back. Quarters of A and B with a C on the exam, on a 40/40/20 split, give 4 × 0.4 + 3 × 0.4 + 2 × 0.2 = 3.2, which rounds to a B. Check your handbook: point-based and percent-based averaging can disagree near a boundary.
Year-long coursesA full-year course often has two semester grades, and each semester grade counts separately on the transcript and in your GPA. The high school GPA calculator takes semester grades as 0.5-credit rows if that is how your school counts them.
Tips before the semester exam
- Know your quarter grades exactly. A rounded report-card grade (B+) hides whether you are at 87% or 89.9%, and that difference changes the exam score you need by about 12 points on a 20% exam.
- Check for exemptions. Some schools exempt students with high grades or good attendance from the semester exam. Then the semester grade is just the quarter average.
- Plan by questions, not percent. Turn the needed percent into a number of questions you can miss with the test grade calculator.
For one class with a final exam that is not split into quarters, use the main final grade calculator. For categories inside a quarter (homework, quizzes, tests), the weighted grade calculator gives each quarter grade first.
Frequently asked questions
How do you calculate a semester grade?
Multiply each quarter grade and the exam by their weights and add the results. At 40/40/20, quarters of 88% and 84% and an exam of 79% give 84.6%.
How much is a semester exam worth?
It is set by your school or district. Splits like 40/40/20 (exam 20%) and 45/45/10 (exam 10%) are common examples; some schools have no exam.
Is a semester grade just the average of two quarters?
Only when there is no semester exam or the exam weight is 0%. Then each quarter counts 50%.
What do I need on my semester exam to get a B?
Use (80 − quarter average × (1 − exam weight)) ÷ exam weight. With an 86% average and a 20% exam: (80 − 68.8) ÷ 0.2 = 56%.