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Assignment Grade Calculator
Convert one assignment score to a percentage and see how much it moves your course grade.
StudentsThis assignment contributes 12.6 course points. Combined with a 90% average on the remaining 85% of the course, your course grade becomes 89.1%.
One assignment, two questions: what did I get on it, and how much does it matter? This calculator answers both. Enter the points you earned and the points possible for the percentage and letter grade, then add the assignment weight in your course to see the grade points it contributes, and how your course average moves if you already know it.
How to use the Assignment Grade Calculator
- Enter the points you earned on the assignment.
- Enter the points it was marked out of.
- Optionally enter its weight in the course, and your current average on the rest.
- Read the assignment grade and its effect on your course grade.
Formula
If an assignment worth 15% of the course is scored at 88%, it contributes 88 x 0.15 = 13.2 points toward the final course percentage.
Worked example
An essay is marked 42 out of 50, which is 84%, a B. The essay carries a 15% course weight, so it contributes 12.6 course points. A student holding a 90% average on the other 85% of the course finishes at 90 x 0.85 + 12.6 = 89.1%, just under the A boundary, which shows how one mid-weight assignment can decide a letter.
Good to know
Students routinely overestimate the impact of small assignments and underestimate mid-weight ones. A homework task worth 2% can only move a course grade by a fraction of a point even at zero, while a 15% essay swings it by over two points. When time is short, the weight column of your syllabus is the priority list. This calculator makes that concrete for a single piece of work before you decide where the evening goes.
US grading scale reference
The table below is the US plus/minus scale used across this site. Where this tool offers other scales, the Canadian scale sets an A from 85% with a pass at 50%, and the Australian scale uses the bands HD (85%+), D (75-84%), C (65-74%), P (50-64%) and F (below 50%) on a 7.0 GPA.
| Letter grade | Percentage | GPA points |
|---|---|---|
| A+ | 97–100% | 4.0 |
| A | 93–96% | 4.0 |
| A- | 90–92% | 3.7 |
| B+ | 87–89% | 3.3 |
| B | 83–86% | 3.0 |
| B- | 80–82% | 2.7 |
| C+ | 77–79% | 2.3 |
| C | 73–76% | 2.0 |
| C- | 70–72% | 1.7 |
| D+ | 67–69% | 1.3 |
| D | 63–66% | 1.0 |
| D- | 60–62% | 0.7 |
| F | 0–59% | 0.0 |
Frequently asked questions
How much does one assignment affect my grade?
By its weight multiplied by the gap from your average. A 15% assignment scored 10 points below your average costs you 1.5 course points; a 2% assignment costs 0.2.
What grade is 42 out of 50?
84%, a B on the US standard and plus/minus scales. In Canada it is an A-, and in Australia a Distinction.
Should I redo a low-weight assignment for a better grade?
Only if the time cost is low. Compute the maximum gain first: weight times the points you could recover. The calculator shows the contribution directly.
How do late penalties change the calculation?
Apply the penalty to the points first, for example a 10% deduction on 42/50 leaves 37.8 points, then enter the adjusted score. The percentage and contribution follow from it.
Can I use this for a group project grade?
Yes, the maths is identical. If your teacher applies an individual multiplier to the group mark, adjust the points by that multiplier before entering them.
Go deeper
Prefer the full walkthrough? Read our guide: How to Calculate a Weighted Grade — it explains the method step by step with more worked examples.
Sources & further reading
- Education Week — grading and assessment coverage — Reporting and research on classroom grading practice for K-12 educators.
- ASCD — resources on fair and accurate grading — Professional guidance for educators on assessment and reporting.
Related tools
Last reviewed: November 2026. Results from this calculator are estimates based on the published scales above; your school's recorded grade is the official one.