What Score Do I Need on My Final Exam?

The formula

Let the points you have banked so far be B (in percentage points of the whole course), the weight of the final exam be W (as a percentage), and your target overall grade be T. The score you need on the final, as a percentage, is:

needed = (T − B) ÷ W × 100

Example: Coursework is 60% of the course and you averaged 72% on it, so you have banked 0.72 × 60 = 43.2 points. The final is worth 40%. To finish with 70%: (70 − 43.2) ÷ 40 × 100 = 67%. You need 67% on the final.

Three possible outcomes

• Reachable: the needed score is between 0% and 100%. Plan your revision around that mark.
• Already secured: the needed score is zero or negative. Even a poor exam would not drop you below the target (check for minimum-pass rules on the exam itself).
• Impossible: the needed score is above 100%. Under the numbers you entered, the target cannot be reached, so it is better to know now and pick a realistic target or ask about options.

Check that the weights add up

Completed assessments plus the final should total 100%. If they total less, some assessment is missing from your list; if more, a weight was entered wrongly. Guessing the gap is zero can produce a confident but wrong answer, which is why this site's calculator stops and asks you to fix the weights.

A second example with marks out of different totals

Suppose the course has a lab report (15%), two problem sets (25% together), a midterm (20%) and a final (40%). Your lab report was 17 out of 20 and the problem sets were 43 out of 50. The midterm was 61 out of 80.

• Lab report: 17 ÷ 20 = 85%, and 85% of 15 is 12.75 points.
• Problem sets: 43 ÷ 50 = 86%, and 86% of 25 is 21.5 points.
• Midterm: 61 ÷ 80 = 76.25%, and 76.25% of 20 is 15.25 points.
• Points banked: 12.75 + 21.5 + 15.25 = 49.5 out of 60 available.

Example: To finish with 75% overall, you need (75 − 49.5) ÷ 40 × 100 = 63.75% on the final. For 80%, you need (80 − 49.5) ÷ 40 × 100 = 76.25%. Each extra five points of overall grade costs 12.5 points on the exam, because the final is worth 40%.

What the calculator cannot know

Always treat the result as planning guidance and confirm important decisions against your syllabus or instructor.

• Course-specific rules such as a minimum mark you must achieve on the final to pass.
• Dropped or replaced scores, curves, and rounding rules applied by your instructor.
• Marks that are not yet released, which you should leave out rather than estimate.

Using the result well

If the required score is high, work backwards: which topics carry the most marks on the exam, and where were you weakest on earlier assessments? If it is comfortably low, avoid complacency but you can spend your time on other courses. Recalculate after each new mark is released, because the answer moves every time.