Grade Calculator
With an 85 current grade and a final worth 20 percent of the course, you need a 60 percent on the final to finish with an 80 percent overall. This grade calculator solves the exact weighted-average question students ask at the end of a term: what do I need on my final to get a B, an A, or just pass the class? Enter your current grade, enter how much of the course is already completed, enter the grade you want overall, and enter the final exam weight. The tool returns the exact required score on the final and tells you whether the target is achievable, already secured, or mathematically out of reach. This is useful because weighted grades are hard to estimate by feel. A strong current grade can mean you only need a modest final score, while a heavy final exam can still move the course average a lot. The calculator helps with semester planning, exam prep, scholarship cutoff checks, pass-fail decisions, and last-minute study prioritization. It also prevents a common mistake: assuming you need the same score on the final as the overall grade you want, even when the final counts for only part of the course.
Quick answer
Your current coursework contributes one weighted share of the total course grade, and the final exam contributes the remaining share.
What this tells you
- •Your current coursework contributes one weighted share of the total course grade, and the final exam contributes the remaining share.
- •The completed weight and final weight must add up to 100 percent for the calculation to make sense.
- •If the required final score is above 100 percent, your target grade is not reachable under the current weights without extra credit or a grading change.
- •If the required final score is below 0 percent, your target is already guaranteed before the final.
- •This tool answers the exact weighted-average question rather than giving a rough guess.
How to Use
- 1Enter your current grade as a percentage, such as 82, 88.5, or 91. This should reflect the course average before the final exam.
- 2Enter the completed weight, which is the percent of the course already represented by that current grade. If assignments before the final count for 80 percent of the course, enter 80.
- 3Enter your target grade, which is the overall course grade you want to finish with, such as 70 to pass, 80 for a B, or 90 for an A cutoff.
- 4Enter the final exam weight. This is the percent of the course grade controlled by the final. The completed weight and final weight together must equal 100.
- 5Read the Required Final Score result and the Status message. If the tool says the target is already secured or not achievable, use that status to guide your planning instead of focusing only on the percentage.
How It Works
Formula
Required final score = (target grade - current grade × completed weight) ÷ final weightThe calculator solves a weighted-average equation. Your final course grade equals the current grade multiplied by the completed weight plus the final exam score multiplied by the final weight, with both weights written as fractions of 100. To isolate the final exam score, the tool subtracts the weighted contribution of your current grade from the target grade and divides the remainder by the final weight fraction. For example, if your current grade is 85, your completed weight is 80 percent, your target grade is 80, and the final is worth 20 percent, the equation is 80 = 85 × 0.80 + final × 0.20. That becomes 80 = 68 + final × 0.20, so final × 0.20 = 12 and the required final score is 60.
Calculation note: values are processed in the order shown above, using the current input units.
Worked Examples
Need a B with an 85 going into a 20 percent final
Your current work already contributes 68 points toward the final course average because 85 × 0.80 = 68. To finish at 80, you need 12 more points from the final, and 12 ÷ 0.20 = 60. This is a common case where a strong current average gives you a lot of breathing room.
Reach an A from a strong B
Your completed work contributes 66 points because 88 × 0.75 = 66. To finish at 90 overall, you need 24 points from a final worth 25 percent. Dividing 24 by 0.25 gives 96, so you need an excellent final to lift the course from 88 to 90.
Find the score needed to pass
The current course work contributes 50.4 points because 72 × 0.70 = 50.4. To finish at 70, the final must add 19.6 points. Since the final weight is 0.30, the needed score is 19.6 ÷ 0.30 = 65.33. This is a practical pass-threshold check before exam week.
Target already secured
A negative required score means the target is already guaranteed. Here, your completed work contributes 84.6 points, which is already above the 80-point target. The tool still shows the raw math, but the important part is the status message that says the goal is already secured.
Target not achievable
The math shows the target cannot be reached under the current weights because the required score is above 100 percent. Your current work contributes 55.25 points, so you would need 34.75 more points from a final worth only 15 percent. That requires 231.67 percent on the exam, which signals the target is mathematically out of reach without extra credit or a grade-policy change.
Required Final Score to Finish With 80 Percent
These examples assume the completed coursework counts for 75 percent and the final exam counts for 25 percent.
| Current grade | Final needed for 80% overall |
|---|---|
| 75% | 95% |
| 78% | 86% |
| 80% | 80% |
| 82% | 74% |
| 85% | 65% |
| 88% | 56% |
| 90% | 50% |
| 95% | 35% |
If your course uses different weights, use the calculator for the exact answer instead of this quick table.
Why final exam weight changes everything
A final exam worth 10 percent has limited power to move the overall grade, so even a very high exam score may not rescue a weak course average. By contrast, a final worth 30 or 40 percent can change the total grade much more dramatically, for better or worse.
That is why two students with the same current grade can need very different final scores depending on the course structure. The key variables are not just the current average and target grade, but also how much of the course is already locked in and how much is still riding on the final.
Common mistakes
- Entering point totals instead of percentages. This tool expects grades and weights as percentages, not raw points from a gradebook.
- Using weights that do not add to 100. If completed weight and final weight do not total 100 percent, the weighted-average equation is incomplete.
- Confusing the current grade with the target grade. The current grade is what you have now, while the target is the result you want at the end.
- Ignoring the status message. A result above 100 or below 0 is not a normal score target, it is a signal that the goal is either impossible or already secured.
- Using the wrong final weight from the syllabus. A small mistake in the weight can change the required score a lot, especially in courses with heavy finals.
Embed this calculator on your site
Drop this single line where you want the calculator to appear. It is responsive, mobile-friendly, resizes automatically, and is free to use with attribution.
<script src="https://calctide.com/embed.js" data-tool="grade-calculator" async></script>Preview the embed at /embed/grade-calculator/.