How to Calculate the Final Exam Score You Need

Three weeks before the final, the only useful question is “what do I need to score?” The answer comes from one rearranged equation.

The formula

Your final course grade is current grade × (1 − weight) + final score × weight, where weight is the final’s share as a decimal. Solve for the final score: needed = (target − current × (1 − weight)) ÷ weight.

Suppose you have 82%, the final is worth 30%, and you want 85%. The coursework counts for 70%, which contributes 82 × 0.7 = 57.4 points. You need 85 − 57.4 = 27.6 more, from a 30% share, so 27.6 ÷ 0.3 = 92%.

Using the calculator

1. Open the Grade Calculator.
2. Enter your current grade, the final’s weight (1 to 100) and the grade you want.
3. Read the score needed.

It treats your current grade as the grade for everything else in the course. If your course has a few assignments still to come, treat those as part of the unknown rather than assuming your average will hold.

When the target is not reachable

Try 70% current, a 40% final and a 90% target. The tool answers that you would need 120%, above the maximum of 100%. That is useful in itself: you can aim for a lower target, ask about extra credit, or plan your effort elsewhere. A needed score of zero or below means the target is already safe.

Check the rules first

• Some courses drop the lowest score, or replace a weak test with the final. This formula ignores those rules.
• Some instructors round at the end. Check whether 89.5% counts as an A−.
• If the syllabus grades by points rather than percentages, convert them first with the points-to-percentage guide.

Frequently asked questions