I Have a 90 in the Class — What Do I Need on the Final?
Going into the final with a 90%: if the final is worth the typical 20%, you need 90% for an A and 40% for a B. Every common weight is below — or set your exact numbers in the calculator.
Runs entirely in your browser — nothing is saved or sent anywhere.
What you need at every final-exam weight
| Final worth | For A | For B | For C | For Pass (D) |
|---|---|---|---|---|
| 10% | 90% | Locked in ✓ | Locked in ✓ | Locked in ✓ |
| 15% | 90% | 23.3% | Locked in ✓ | Locked in ✓ |
| 20% | 90% | 40% | Locked in ✓ | Locked in ✓ |
| 25% | 90% | 50% | 10% | Locked in ✓ |
| 30% | 90% | 56.7% | 23.3% | Locked in ✓ |
| 40% | 90% | 65% | 40% | 15% |
| 50% | 90% | 70% | 50% | 30% |
Reading this table
"Locked in" means even a zero on the final keeps that grade. "Not possible" means a perfect final still wouldn't get you there — with a 90% and a heavily weighted final, your ceiling is 95% (50% weight) to 91% (10% weight). The math: needed = (target − current × (1 − weight)) ÷ weight.
Worth knowing
Ask about rounding before finals week
An 89.5 is an A- in some classes and a B+ in others. Professors have wildly different rounding policies, and the polite time to ask is mid-semester, not the night grades post.
The final isn't all-or-nothing
Because finals are usually worth 20–40%, your semester of work is protecting you more than you think. Run the numbers: the score you actually need is often lower — sometimes dramatically lower — than the panic estimate.
Common questions
Do these calculators store my grades?
No. Everything is computed in your browser the moment you press Calculate — nothing is uploaded, saved or seen by anyone else. Refresh the page and it's gone.
How are letter grades calculated from percentages?
Most US schools map percentages to letters in 10-point bands: 90–100 is an A range, 80–89 a B range, 70–79 a C range, 60–69 a D range, and below 60 an F. Plus/minus splits each band roughly in thirds (e.g. 90–92 = A-, 93–96 = A, 97+ = A+). Individual schools and professors can and do vary the cutoffs.