Missing Grade Calculator
A missing grade calculator answers one of the most common questions in any course: "What do I need to score on this upcoming assignment to hit my target grade?" The tool takes your current overall grade, the grade you want to finish with, and the percentage weight that the upcoming assignment contributes to your final grade. It then works backward through the weighted average formula to find the exact score required on that assignment. The result includes the letter grade that score corresponds to, and a clear indication of whether the score is achievable (that is, 100% or below). If the required score comes back above 100%, the calculator flags this as not achievable, which is a useful signal to either adjust your target or speak with your instructor about extra credit or grade correction. If the required score is zero or negative, you have already secured your target regardless of performance on this assignment. The formula is the inverse of a weighted average and is used widely in academic advising. Results update live as you type, so you can adjust your target grade to explore realistic scenarios.
You need --% on the assignment (--).
How the missing grade formula works
When a course uses weighted grading, the final grade is the sum of each assignment's score multiplied by its weight. To find the unknown assignment score, rearrange the formula to isolate it.
Required = (Desired - Current x (1 - Weight/100)) / (Weight/100)
Worked example
Current grade: 78%. Desired grade: 85%. Assignment weight: 20%.
- Remaining weight of existing work: 1 - 20/100 = 0.80
- Existing grade contribution: 78 x 0.80 = 62.4
- Points still needed from assignment: 85 - 62.4 = 22.6
- Required score: 22.6 / (20/100) = 22.6 / 0.20 = 113.00%
- 113% exceeds 100%, so this target is not achievable with this assignment alone.
Letter grade scale used
| Letter | Score range |
|---|---|
| A | 90% to 100% |
| B | 80% to 89% |
| C | 70% to 79% |
| D | 60% to 69% |
| F | Below 60% |
Missing grade calculator: frequently asked questions
How do I calculate what I need on a missing assignment?
Use the formula: required score = (desired overall grade - current grade x (1 - weight/100)) / (weight/100). For example, if your current grade is 78%, you want an 85% overall, and the assignment is worth 20%: required = (85 - 78 x 0.80) / 0.20 = (85 - 62.4) / 0.20 = 22.6 / 0.20 = 113%. Since 113% exceeds 100%, achieving an 85% overall is not possible on this assignment alone.
What does it mean when the required score is above 100%?
A required score above 100% means your current grade is too low to reach the desired overall even with a perfect score on the assignment. You would need to either lower your target grade or find other ways to improve your grade (extra credit, other remaining work). This calculator shows 'Not achievable' in that scenario so you know immediately.
What does a required score of 0 or below mean?
A required score at or below 0 means your current grade is already high enough that you will hit the desired overall even if you score 0 on the upcoming assignment. You have banked enough grade points elsewhere that this particular assignment cannot drag you below your target, regardless of how you score on it.
What if the assignment weight is more than 50%?
High-weight assignments (midterms, final projects) give you more leverage to raise or lower your grade. A 50% weighted assignment can shift your grade by up to 50 percentage points, making the required score calculation even more important. Enter the exact weight listed on your syllabus, which should sum to 100% across all assignments in your course.
Can I use this for multiple remaining assignments?
This calculator is designed for a single upcoming assignment. If you have several remaining assignments of equal weight, divide the remaining weight equally among them and use the required-grade calculator instead. For a more complex scenario with multiple assignments of different weights, work through each one individually, updating your current grade as you go.
Official sources
- National Center for Education Statistics grading indicator: Condition of Education, Indicator TGR.
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. See our methodology. General information only; confirm your course weighting with your syllabus.