To calculate your grade, divide the points you earned by the points possible and multiply by 100. 172 out of 200 points is 172 ÷ 200 × 100 = 86%, a B on the usual scale. If your teacher weights categories such as homework, quizzes and tests, find your average in each category first, then multiply each average by its weight and add the results.
The Grade Calculator handles both methods and tells you the average you need on the rest of the course, and the Final Grade Calculator works out the score you need on your final. Here is the math behind them.
Method 1: total points
Use this when every assignment is worth points and your grade is simply your share of all the points.
- Add up the points you earned: 45 + 38 + 89 = 172.
- Add up the points possible: 50 + 50 + 100 = 200.
- Divide and multiply by 100: 172 ÷ 200 × 100 = 86%.
A single assignment works the same way: 45 out of 50 is 45 ÷ 50 × 100 = 90%.
Method 2: weighted categories
Most syllabi weight categories, for example homework 20%, quizzes 30% and tests 50%. A category's weight is the share of the final grade it controls, no matter how many points it contains.
- Find your average in each category, as a percentage.
- Multiply each average by its weight written as a decimal.
- Add the results.
| Category | Weight | Your average | Weight × average |
|---|---|---|---|
| Homework | 20% | 95% | 19.0 |
| Quizzes | 30% | 82% | 24.6 |
| Tests | 50% | 78% | 39.0 |
| Course grade | 100% | 82.6% |
0.20 × 95 + 0.30 × 82 + 0.50 × 78 = 82.6%, a B− on a plus/minus scale.
When some categories have no grades yet
Early in the term, divide by the weights you have completed instead of by 100%. If no tests have happened yet: (19.0 + 24.6) ÷ 0.50 = 87.2%. That is your current grade, but it can still move a long way, because tests are half of the course.
How to calculate the grade you need on the final
If you know your current grade and how much the final is worth, the score you need is:
Needed = (Target − Current × (1 − Final weight)) ÷ Final weight
With a current grade of 84%, a final worth 25% and a target of 85%:
(85 − 84 × 0.75) ÷ 0.25 = (85 − 63) ÷ 0.25 = 88%
| Target course grade | Score needed on the final |
|---|---|
| 80% | 68% |
| 85% | 88% |
| 90% | 108%, out of reach without extra credit |
The same numbers answer "what if" questions in reverse: a 70% on that final would give 84 × 0.75 + 70 × 0.25 = 80.5%.
Grade percentage to letter grade
Scales vary by school, so check your syllabus. This plus/minus scale is common in the US:
| Letter | Percent | Letter | Percent |
|---|---|---|---|
| A+ | 97–100 | C+ | 77–79 |
| A | 93–96 | C | 73–76 |
| A− | 90–92 | C− | 70–72 |
| B+ | 87–89 | D+ | 67–69 |
| B | 83–86 | D | 63–66 |
| B− | 80–82 | D− | 60–62 |
| F | below 60 |
Many schools skip plus and minus grades and use 90, 80, 70 and 60 as the cut-offs for A, B, C and D.
How to calculate a grade average
Averaging percentages and adding up points give different answers when assignments are different sizes. Say you scored 9/10 (90%) on a quiz and 40/50 (80%) on a test:
- Average of the percentages: (90 + 80) ÷ 2 = 85%.
- Total points: 49 ÷ 60 = 81.7%.
Total points is right when the course is graded by points; the simple average is right only when every assignment counts equally. In a weighted course, average within each category the way your teacher does, then weight the categories.
From grades to GPA
Your GPA turns each final letter grade into grade points (A = 4.0, B = 3.0 and so on) and averages them, weighted by credits. Use the GPA Calculator, and see what counts as a good GPA and the full GPA scale chart.
Common questions
How do I calculate my grade percentage? Divide the points you earned by the points possible and multiply by 100: 45 out of 50 is 90%.
How do I calculate my grade when categories are weighted? Multiply each category's average by its weight and add the results. The table above comes to 82.6%.
Why is my grade different from the average of my scores? Weighting and assignment size. A 100-point test moves your grade more than a 10-point quiz, and a test category worth 50% outweighs homework worth 20%.
How much can the final raise my grade? At most the final's weight times the gap between a perfect score and your current grade. With a final worth 25%, a 100% lifts an 84% to 84 × 0.75 + 100 × 0.25 = 88%.