Enter 30 if the final is worth 30% of your grade
Required Final Score
Required = (Target − Current × (1 − Weight)) / Weight All percentages as decimals (e.g. 85% = 0.85)

Derived by solving the weighted average equation for the missing component. Rearranges: Target = Current × (1-w) + Final × w

Current in A1, weight% in B1, target in C1
=(C1-A1*(1-B1/100))/(B1/100)

The Math Behind "What Do I Need on My Final?"

This is one of the most-searched calculations by students in the weeks before finals. The math rearranges the weighted average formula to solve for the unknown final exam score. If your final grade is a weighted combination of your current grade and your final exam grade, then: Final Grade = Current Grade × (1 - Final Weight) + Final Score × Final Weight. Solving for Final Score: Final Score = (Target - Current × (1 - Final Weight)) / Final Weight.

Example: you have an 82% in the course, the final is worth 30%, and you want to earn 85% overall. Required final score = (85 - 82 × 0.70) / 0.30 = (85 - 57.4) / 0.30 = 27.6 / 0.30 = 92%. You need a 92% on the final to reach 85% overall.

What to Do When the Required Score Is Over 100%

If the calculator returns a required score above 100%, your target is mathematically impossible given your current grade and the final exam's weight. This is a clear signal to recalibrate your target. Work backwards: what is the maximum possible final grade if you score 100% on the final? That calculation is: Max Grade = Current × (1 - Final Weight) + 100 × Final Weight. If the maximum achievable grade still doesn't reach your original target, it's time to have a conversation with your professor about extra credit options or to plan strategically for next semester.

Using This Strategically Throughout the Semester

This calculator is most useful not just at the end of the semester, but throughout it. After each major assignment, recalculate what you need on remaining work to hit your target. This gives you advance warning if you're in danger of missing your goal, while there's still time to adjust — study harder, seek tutoring, or attend office hours before the situation becomes urgent.

Students who track this throughout the semester avoid the unpleasant surprise of realizing in the final week that their target grade has become mathematically impossible. Early awareness creates options; late awareness creates panic.

Weighted Grades and Different Assignment Categories

Many courses use multiple weighted categories — homework, midterms, quizzes, participation, and a final exam, each worth a different percentage of the grade. This calculator works for a two-component model (current grade and final), but you can extend the logic: for any remaining assignment, solve for the score needed in that component while holding all other known grades constant. The algebra is identical, just applied to one component at a time.

Pay close attention to how professors calculate grades when multiple assignments exist within a category. Some drop the lowest score; some weight later assignments more heavily; some require passing all components separately. These details are in your syllabus and can significantly affect the calculation.

Frequently Asked Questions

If the result exceeds 100%, your target is mathematically impossible given your current score and the final's weight. Consider adjusting your target or asking about extra credit.
Add up the total weight of all remaining work and use that as the "final weight." The result will be the average score you need across all remaining assignments.
Final grade = Current × (1 - final_weight) + Final_score × final_weight. Solving for Final_score gives the formula above.