What Do I Need on My Final? Formula, Examples and Table

To find the score you need on your final exam, use:

Write the weight as a decimal: a final worth 25% is 0.25. If your current grade is 84%, the final is worth 25%, and you want an 80% in the course:

(80 − 84 × 0.75) ÷ 0.25 = (80 − 63) ÷ 0.25 = 68%.

That’s the whole method. The rest of this guide shows how to get your current grade right (the step most people get wrong), what to do in a points-based class, and how to read the answer. The grade calculator does all of it, including a table of the score you need for each letter grade.

Why the formula works

Your final course grade is a weighted average of two parts: everything before the final, and the final itself.

Put in the grade you want and solve for the final score, and you get the formula above. It assumes your current grade already covers everything except the final. If some homework or a project is still ungraded, see the section on missing work below.

Step 1: Work out your current grade properly

Most syllabi weight categories differently. Say your class is graded like this:

Your current grade is the weighted average of the categories you’ve completed, divided by the weight completed so far:

(0.20 × 91 + 0.15 × 84 + 0.15 × 88 + 0.25 × 76) ÷ 0.75 = (18.2 + 12.6 + 13.2 + 19.0) ÷ 0.75 = 63.0 ÷ 0.75 = 84.0%

A common mistake is to average the four category scores: (91 + 84 + 88 + 76) ÷ 4 = 84.75%. In this case it’s close, but in a class where the midterm counts for 40%, a straight average can be several points off.

Your school’s online gradebook may already show a weighted current grade. Check that it uses the same weights as your syllabus, and whether it counts ungraded work as zero.

Step 2: Find the score you need for each grade

With 84.0% now and a final worth 25%:

How to read it:

• Over 100%: that grade is out of reach on the final alone. Here an A would need 108%, so unless there’s extra credit or a curve, B is the realistic target.
• Between 0% and 100%: that’s your goal. A 68% gets a B.
• Below 0%: you’ve already secured that grade, even with a zero on the final. (Check your syllabus, though: some classes require you to pass the final to pass the course.)

Points-based classes

Some classes add up points instead of using weights. Then the maths is simpler:

Example: you have 412 of 480 points so far (85.8%), and the final is worth 120 points, so the course has 600 in total.

Notice that a points class can behave differently from a weighted one. Here the final is 20% of the course (120 of 600 points), so it moves your grade less than a 25% final would.

What if some work is still ungraded?

If you still have a project or homework due before the final, you have two unknowns. The easiest approach is to estimate the missing score from your usual performance, add it to your current grade, and then solve for the final.

Example: your completed work makes up 70% of the course and averages 84%. A project worth 5% is still due, and you expect about 90% on it. Your estimated grade before the final is (0.70 × 84 + 0.05 × 90) ÷ 0.75 = (58.8 + 4.5) ÷ 0.75 = 84.4%. Use that as your current grade, with 0.25 as the final weight, as before. The grade calculator lets you enter an estimate and shows how much weight is still open.

Things that change the answer

• Dropped lowest scores. Many teachers drop the lowest quiz or homework. Recalculate the category average without it.
• Final replaces the midterm. Some courses let a higher final score replace a lower midterm score. That can make the final worth much more than its listed weight.
• Rounding rules. An 89.5% may or may not round to an A. Ask, but don’t count on it.
• Letter cut-offs. Not every school uses 90/80/70/60. Plus and minus grades and different cut-offs (93 for an A, for example) change the targets. Use the scale on your syllabus.
• Curves. If grades are curved, your raw percentage matters less than your position in the class.

Turning the result into a study plan

1. Pick the realistic target. If an A needs 108%, aim for the B and give yourself margin: plan for 75%, not exactly 68%.
2. Check past exams. If your midterm was 76% and you need 68%, you’re in good shape. If you need 90% after scoring 65% on the midterm, change how you study, not just how long.
3. Look at the grade’s effect on your GPA. A B instead of a C in a 4-credit class is worth 4 grade points on your transcript. The GPA calculator shows the effect on your term and cumulative GPA, and our guide on how to calculate GPA explains the weighting.

FAQ

How do I calculate what I need on my final?

Subtract your current grade times (1 − final weight) from your target, then divide by the final weight. With 84% now, a 25% final and a target of 80%: (80 − 63) ÷ 0.25 = 68%.

What if my final is worth 50%?

The same formula works. With 72% now and a target of 80%: (80 − 72 × 0.5) ÷ 0.5 = (80 − 36) ÷ 0.5 = 88%. A heavy final gives you more room to change your grade, in either direction.

Can I fail the class if I get a zero on the final?

Use the formula with a score of 0: your grade would be current grade × (1 − final weight). With 84% and a 25% final, that’s 63%, a D on a standard scale. Some courses also require a minimum score on the final to pass, so check your syllabus.

Why is my gradebook grade different from my calculation?

The gradebook may count missing or ungraded work as zero, use different weights, or include extra credit. Compare its category weights with your syllabus.