How the score you need is calculated
Your final grade is a mix of the grade you have now and your final exam score, weighted by how much the final counts. Solving that for the exam score gives:
needed = (desired − current × (1 − w)) ÷ w
Here w is the final's weight as a decimal (30% = 0.30). The part current × (1 − w) is what you have already banked; the final has to make up the rest.
Worked example
Your current grade is 84%, the final is worth 30%, and you want 85% overall.
Banked: 84 × 0.70 = 58.8 points
Still needed: 85 − 58.8 = 26.2, and 26.2 ÷ 0.30 = 87.33%
So you need about 87.3% on the final. A zero would leave you at 58.8%, and a perfect score would give you 88.8%.
Frequently asked questions
What should I use as my "current grade"?
Your grade on everything graded so far, not counting the final. That's usually the percentage your school portal shows before the final is entered. If your portal already counts the final as a zero, work out your grade without it using the grade calculator.
What does it mean if I need more than 100%?
Your goal can't be reached with the final alone. The calculator shows the highest grade you can still get with a perfect score. Extra credit, a curve or a retake policy might change that, so it's worth asking your teacher.
What if the score needed is 0% or less?
Your target is already locked in: even a zero on the final keeps you at or above it. Check the syllabus anyway, because some courses require you to take or pass the final to pass the class.
How do I find out how much my final is worth?
It's in your syllabus, usually in a grading breakdown. If the class uses points, divide the final's points by the total points in the course: a 200-point final in a 1,000-point course is worth 20%.
Does this work for a test or project that isn't a final?
Yes. It works for any single remaining piece of work. Enter its weight in place of the final's weight.
Can I type a letter grade?
Yes. For the grade you want, a letter means the bottom of that range, so B means 83% and A− means 90%. For your current grade, a letter counts as the middle of its range, so an exact percentage is more accurate.