How to Calculate the Score You Need on a Final Exam

Not sure if you can still hit your target grade? Use the final grade formula — or the free calculator below — to find out exactly what exam score you need.

The Final Grade Formula

Required Exam Score = (Target Grade − Current Grade × (1 − Final Exam Weight)) ÷ Final Exam Weight

Where:

  • Target Grade — the overall course grade you want to achieve (as a percentage)
  • Current Grade — your grade so far, before the final exam (as a percentage)
  • Final Exam Weight — how much the final exam contributes to your overall grade (as a decimal: 40% = 0.40)

Worked Examples

Example 1: Can I still get an A?

Current grade: 76%

Target grade: 90%

Final exam weight: 30%

(90 − 76 × 0.70) ÷ 0.30 = (90 − 53.2) ÷ 0.30 = 36.8 ÷ 0.30

Required: 122.7% — Not achievable. You cannot reach 90% overall.

Example 2: Can I pass the course?

Current grade: 58%

Target grade: 60%

Final exam weight: 40%

(60 − 58 × 0.60) ÷ 0.40 = (60 − 34.8) ÷ 0.40 = 25.2 ÷ 0.40

Required: 63.0% — Achievable. You need 63% on the final to pass.

Example 3: Maintaining a B

Current grade: 85%

Target grade: 80%

Final exam weight: 25%

(80 − 85 × 0.75) ÷ 0.25 = (80 − 63.75) ÷ 0.25 = 16.25 ÷ 0.25

Required: 65.0% — You only need 65% on the final to maintain an 80% overall.

When the Required Score Exceeds 100%

If the formula returns a score greater than 100%, your target grade is mathematically not achievable with the remaining work. In this case, you should:

  • Recalculate with a lower target grade to see what is still achievable.
  • Check whether extra credit opportunities are available.
  • Speak with your instructor about your academic standing.
  • Review your institution's grade policy on incomplete courses or deferred exams.

Frequently Asked Questions

How do I know how much my final exam is worth?
Check your course syllabus or assignment guide. The weight of the final exam is usually listed as a percentage of your total grade (e.g. 'Final exam: 35% of course grade').
What if my course uses letter grades, not percentages?
Convert letter grades to percentages first. Typical conversions: A = 93%, A− = 90%, B+ = 87%, B = 83%, C = 73%. Use the midpoint of any grade range your institution specifies.
Does this formula work for courses with multiple components?
Yes, as long as you can calculate your overall current grade as a weighted average of all completed components, and you know the weight of the remaining assessment.