How to calculate the score you need on your final
Here it is with your numbers:
- Turn the weight into a decimal: 25 ÷ 100 = 0.25.
- Work out what the rest of the course adds: 88 × (1 − 0.25) = 66.
- Subtract that from your target: 90 − 66 = 24.
- Divide by the weight: 24 ÷ 0.25 = 96%.
It means you need 96% on the final to finish with 90%. A perfect 100% would give 91%.
The formula is the usual weighted average, current × (1 − weight) + final × weight, solved for the final score. It’s the same rule school gradebooks such as Canvas use.
Source Instructure (Canvas) · How weighted course grades are calculated ↗
What you need for each letter grade
| Grade | Percent | Score needed on the final |
|---|---|---|
| AYou | 90 – 100% | 96% |
| BYou | 80 – 89% | 56% |
| CYou | 70 – 79% | 16% |
| DYou | 65 – 69% | Already secured |
A score above 100% isn’t possible unless your teacher offers extra credit on the exam, so the table says “Not possible” instead. “Already secured” means you’d keep that grade even with 0%. Schools set their own cutoffs, so check your syllabus.
Source College Board · How to calculate your GPA on a 4.0 scale ↗
FAQs
What do I need on my final to get an A?
Put your current grade, the final’s weight and 90 as the grade you want into the calculator. With 88% now and a final worth 25%, you need 96%. The table shows the score for a B, C and D as well.
Source Instructure (Canvas) · How weighted course grades are calculated ↗
How do you calculate your final grade?
Multiply your grade before the final by the share it counts, multiply your final score by the share the final counts, and add the two. With 88% now and 96% on a final worth 25%: 88 × 0.75 + 96 × 0.25 = 90.
How do you calculate a final grade with weights?
Multiply each score by its weight and add the results. Canvas’s example: 75% × 0.20 + 98% × 0.50 + 87% × 0.30 = 15 + 49 + 26.1, which is 90.1%. The Weighted Grade Calculator does this for you.
Sources
- Instructure (Canvas): How weighted course grades are calculated
- College Board: How to calculate your GPA on a 4.0 scale