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Final Grade Calculator

With the defaults — an 88% going in, a final worth 30%, and a 90% target — you would need a 94.7% on the exam. This calculator answers the end-of-semester question directly: given your current grade and the final exam's weight, what score do you need on the final to reach your target? It also shows the scores needed to land an A, a B, or a C.

Needed on the final
94.7%
For an A (90%)
94.7%
For a B (80%)
61.3%
For a C (70%)
28.0%
You need 94.7% on the final
A demanding score, but reachable — the 90% target is still on the table.
Inputs
Current grade
%
Final exam weight
%
Target grade
%
Your grade is mostly already set
Scoring 0 on the final still leaves you at 61.6%, and a perfect final reaches 91.6%. The exam only moves you inside that band.
A lighter final raises the bar
The needed score divides by the exam weight (30%), so a smaller weight amplifies it — the same target demands a higher score when the final counts for less.
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Uses your inputs above
94.7% needed on the final. Want to try a variation?

The math

Reviewed 2026
Formula
needed = (target − current·(1 − w)) / w
w final exam weight as a fraction

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Example: how final grade is calculated

Step-by-step with default inputs

Suppose you put the default values into Final Grade Calculator:

Current grade
88%
Final exam weight
30%
Target grade
90%

Plug those into the formula needed = (target − current·(1 − w)) / w and the result is:

Needed on the final
94.7%

How to calculate final grade by hand

  1. Convert the final exam weight to a fraction: w = 30% = 0.3.
  2. Multiply your current grade by the rest of the course's weight: 88 × (1 − 0.3) = 61.6 points locked in.
  3. Subtract that from your target grade: 90 − 61.6 = 28.4 points must come from the final.
  4. Divide by the exam weight: 28.4 ÷ 0.3 = 94.7% needed on the final.
  5. Sanity-check the answer: 88 × 0.7 + 94.7 × 0.3 ≈ 90.

How does the final grade calculator work?

Your course grade is a weighted average of everything before the final and the final itself: course = current × (1 − w) + score × w, where w is the exam weight as a fraction. Solving for the score gives needed = (target − current × (1 − w)) ÷ w, which is the entire calculation. With an 88% current grade and a 30% final, the locked-in portion is 88 × 0.7 = 61.6 points, so reaching 90 requires (90 − 61.6) ÷ 0.3 = 94.7 on the exam. The calculator flags impossible targets (a needed score above 100%) and already-secured ones (at or below 0%). It assumes the final is the only remaining graded work and that no curve or extra credit applies.

Last reviewed July 2, 2026 · Editorial policy

Frequently asked questions

What do I need on my final to get an A?

Compute (90 − current × (1 − w)) ÷ w. With an 88% average and a final worth 30% of the grade, you need 94.7%; with the same average and a 20% final you would need 98%, because a lighter exam has less power to move the average.

Can I still pass the class if I bomb the final?

Your floor is current × (1 − w) — the grade you would end with after a zero on the final. At 88% with a 30% final, that floor is 61.6%. And scoring even 28% on the exam keeps the course grade at 70%.

Why does the calculator say my target isn't reachable?

Because the required score exceeds 100%. The final can add at most its full weight: at 88% with a 30% final, a perfect exam tops out at 88 × 0.7 + 100 × 0.3 = 91.6%, so any target above that is out of reach on this exam alone.

Does the exam weight really matter that much?

Yes — the needed score divides by w, so a smaller weight amplifies what you must score. Moving from 88 to 90 requires 94.7% when the final is worth 30% but 98% when it is worth 20%. Heavier finals are riskier but give more room to climb.

How accurate is this final grade calculator?

The math is deterministic — the same inputs always produce the same output, and the formula is shown above. Accuracy of the answer for your situation depends on how well your inputs match reality and how well the formula models the question.

How do I share my result?

Hit Share at the top of the page. Every input you change is encoded in the URL, so a permalink reproduces exactly what you see. No account needed.

Guides

What grade do I need on my final exam?The exact score you need on your final: (target − current × (1 − final weight)) ÷ final weight — with what to do when the answer is over 100%.