What do I need on the final to get a B?
Quick answer
With a 80 average and a final worth 25% of the grade, you need a 92 on the final to finish with a 83. The formula: (83 − 80 × 0.75) ÷ 0.25 = 92. Change the numbers below for your class.
You need
92%
on the final to finish with a 83 (B on the common scale). A perfect final tops out at 85; a zero leaves you at 60.
(83 − 80 × (1 − 0.25)) ÷ 0.25 = 92
A 70 on the final
77.5 · C+
A 85 on the final
81.3 · B-
A 100 on the final
85 · B
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The formula, in plain words
Your overall grade is two pieces added together: the part already decided (your current average, times everything the final is not) and the part still open (your final score, times the final’s weight). Set the total equal to your target and solve for the final.
needed on final = (target − current × (1 − weight)) ÷ weight, where weight is a decimal. With an 85 average, a final worth 20% and a target of 90: (90 − 85 × 0.8) ÷ 0.2 = (90 − 68) ÷ 0.2 = 110. That target is out of reach; a 100 on the final tops out at 88.
Where the numbers come from
Your current average is on Canvas or Blackboard under Grades, or you can compute it with the weighted grade calculator if your syllabus lists category weights. The final’s weight is in the syllabus grading table. The target is the letter cutoff on your syllabus, which is not always the common 90/80/70.
If you would rather not type any of this, Classmaite reads the weights out of your syllabus when you upload it and tracks the answer all semester as scores come in.
Common questions, pre-filled
- If my final is worth 20%, what do I need on it?
- If my final is worth 25%, what do I need on it?
- If my final is worth 30%, what do I need on it?
- If my final is worth 40%, what do I need on it?
- If my final is worth 50%, what do I need on it?
- What do I need on the final to pass with a 70?
- Can I still pass the class?
- What do I need on the final to get a B?
- What do I need on the final to get an A?
- If I have a 65 in the class, what do I need on the final?
Frequently asked questions
How is the score I need on the final calculated?
Your overall grade is your current average times the share of the grade already decided, plus your final score times the final’s weight. Solve for the final: needed = (target − current × (1 − weight)) ÷ weight, with the weight as a decimal. The calculator shows this with your numbers filled in.
What if my class uses points instead of percentages?
Divide the final’s points by the total points in the course to get its weight. A 200-point final in a 1,000-point course is worth 20%. Your current average is the points you have earned divided by the points possible so far.
Does this work for a cumulative or weighted final?
Yes. The weight is whatever the syllabus says the final counts for, cumulative or not. If your professor drops a low score or replaces a midterm with the final, recompute your current average first and use the final’s stated weight.
What does “out of reach” mean?
A perfect score on the final would still leave you below the target. The calculator shows the best overall grade you can still reach so you can pick a realistic target instead.
Is my data stored?
No. Everything runs in your browser. If you choose to email yourself the result, only your email address is saved.