The three inputs
You need your current course grade, the final exam’s weight and the course grade you want to finish with. Make sure the current grade is calculated the same way the syllabus describes; some gradebooks show a running grade based only on completed work.
Solve the equation
Let C be the current grade, W the final weight as a decimal, T the target and F the required final score. The model is T = C(1 − W) + FW. Solving for F gives F = [T − C(1 − W)] ÷ W.
Worked example
Current grade 80%, final weight 25%, target 70%: F = [70 − 80(0.75)] ÷ 0.25 = (70 − 60) ÷ 0.25 = 40. Under the simplified model, a 40% final score would finish the course at 70%.
Impossible and unnecessary targets
A required score above 100% usually means the target cannot be reached through the final alone unless extra credit exists. A required score below 0% means the current standing is already high enough that even a zero would meet the target in the simplified model.
Course rules still matter
Some courses require a minimum final-exam score regardless of the average, calculate points instead of weights, or replace a prior exam. Check the syllabus before using the result for a high-stakes decision.
Use several targets
Instead of calculating only one target, try a small range such as 70%, 75% and 80%. Seeing the required final score for several outcomes gives you a more realistic planning picture and can show when an ambitious target would require nearly perfect performance.
Related resources
Reviewed: October 2026. CurioLift explanations are educational; when a school, instructor or required style guide uses different rules, those rules take priority.