What the final grade calculator does
Your final exam is not worth the same in every class. In one course it might count for 10 percent of your grade. In another it might count for 40 percent. That weight changes the score you need. This page runs one formula: required = (target - current x (1 - w)) / w. Here w is the final's weight written as a decimal. A final worth 20 percent means w = 0.2.
The answer is the score you must earn on the final itself. It is not your overall grade. If the answer comes out above 100, the target is out of reach with the final alone.
How to read the formula
The formula splits your grade into two parts. The part already locked in is current x (1 - w). The part still open is the final, which carries weight w. The target minus the locked part leaves the points the final must supply. Divide by w to turn those points into a score on the exam.
Here is a worked example with real numbers. Say your current grade is 88. Your target is 90. The final is worth 20 percent, so w = 0.2.
- Locked part: 88 x 0.8 = 70.4
- Points the final must supply: 90 - 70.4 = 19.6
- Score needed: 19.6 / 0.2 = 98
You need a 98 on the final to finish with a 90. That is a high score, but it is possible.
The same formula also gives your best and worst possible course grades. A perfect final gives current x (1 - w) + 100 x w. A zero gives current x (1 - w). With current 88 and w = 0.2, the best is 90.4 and the worst is 70.4.
When the answer is over 100
A score above 100 cannot happen on a normal exam. The target is out of reach unless something else changes. You have two honest options.
- Talk to your instructor about extra credit. Ask what is available and how it counts. Do this early, not in the last week.
- Re-set your target to a grade you can still reach. Run the numbers again with a lower target and see what score it needs.
Check the best possible grade first. If the best possible grade is below your target, no final score can fix it. If the best possible grade is above your target, the target is still alive.
Finding the final's weight
The weight is the one number people guess wrong. It is usually in the syllabus, the course outline your instructor hands out at the start. Look for a section called grading, grade breakdown, or assessment. It often looks like this:
| Category | Weight |
|---|---|
| Homework | 20% |
| Quizzes | 15% |
| Midterm | 25% |
| Final exam | 40% |
If the syllabus is not clear, ask your instructor. If your course uses a weighted category setup, the weighted grade calculator can help you find your current standing first.
One warning about the letter scale. This site uses the most common US scale: A is 93 to 96, A- is 90 to 92, B+ is 87 to 89, and so on down to F below 60. Schools differ. Your school may use different cutoffs, so check your own grading policy before you trust a letter grade.
What to do with the number
Once you know the score you need, you can plan. A needed score of 70 means steady review is enough. A needed score of 95 means you should start early and study the topics your instructor flagged. A needed score above 100 means a conversation with your instructor comes first.
If you want to see how this final score moves your GPA, the GPA calculator takes your current GPA and credits and adds this term. The full method behind every number on this site is at how we calculate.