About the final grade calculation
Your overall grade is a weighted blend of everything so far and the final exam. Because the final carries a fixed weight, there is a hard ceiling and floor on where you can end up — and sometimes the target you want is already impossible, or already guaranteed, regardless of how the exam goes.
Formula
Needed = (Target − Current × (1 − w)) ÷ w
w = the final exam's weight as a decimal
A result above 100 means the target cannot be reached.
A result at or below 0 means it is already secured.Worked example
Currently at 85%, wanting 90% overall, with the final worth 30%: (90 − 85×0.7) ÷ 0.3 = (90 − 59.5) ÷ 0.3 = 101.7%. Just out of reach — you would need extra credit.
Frequently asked questions
Why does it say I need over 100%?
Because the marks already banked are too low for the target given how little the final is worth. It is a real answer, not an error. Your options are extra credit, a lower target, or checking whether the weighting is what you think.
What if the result is negative?
You have already secured your target grade — even a zero on the final would leave you above it. The negative number is the arithmetic telling you there is slack.
How do I find my final exam weight?
It is in the syllabus or course outline, usually as a percentage of the overall grade. If assessment is split across several components, the final's share is the number you need here.
Does this handle a curve or scaling?
No. It assumes your grades are final as stated. If your course applies a curve, calculate with your pre-curve numbers and treat the result as a floor.
Sources
- Standard weighted-average grade arithmetic