How to calculate your grade with points
Your grade is the sum of the points you earned divided by the sum of the points possible, times 100. Add up the columns first, then divide once. Averaging the percentages of each assignment gives a different, wrong answer whenever assignments are worth different amounts.
class grade = (Σ points earned ÷ Σ points possible) × 100
Worked example
Lab report 18/20, quiz 8/10, unit test 41/50 and project 92/100. Points earned: 18 + 8 + 41 + 92 = 159. Points possible: 20 + 10 + 50 + 100 = 180.
159 ÷ 180 = 0.8833, so the class grade is 88.3%. The plain average of the four percentages (90, 80, 82, 92) would be 86%, which is too low: the 80% quiz is only worth 10 points, but averaging treats it like the 100-point project.
The calculator does the totals for you and shows how many points you are from the next 10% step. The letter uses the plus/minus version of the 10-point scale (B+ from 87%),[2] and the letter grade calculator shows other scales.
Class grade calculator: points vs. weighted categories
Check your syllabus for one of two systems. In a total points class, every point in the gradebook counts the same and this page is the right tool. In a weighted class, categories such as homework, quizzes and tests each carry a fixed percent of the grade, no matter how many points they contain. For that, use the weighted grade calculator.
The same scores can give different grades in the two systems. Take homework at 100/100 and one test at 30/50. With total points, that is 130/150 = 86.7%. If the syllabus says homework is 20% and tests 80%, it is 100 × 0.2 + 60 × 0.8 = 68%. If your online gradebook shows a number that does not match your own total, the class is probably weighted.
How one assignment changes your course grade
A new assignment moves your grade toward its own score, and the bigger its point value relative to what is already graded, the further it moves. The table starts from a class at 85% with 500 points graded (425 earned) and adds one more assignment.
| Assignment worth | Score 100% | Score 90% | Score 70% | Score 50% | Score 0% |
|---|---|---|---|---|---|
| 10 pts | 85.3% | 85.1% | 84.7% | 84.3% | 83.3% |
| 25 pts | 85.7% | 85.2% | 84.3% | 83.3% | 81% |
| 50 pts | 86.4% | 85.5% | 83.6% | 81.8% | 77.3% |
| 100 pts | 87.5% | 85.8% | 82.5% | 79.2% | 70.8% |
| 200 pts | 89.3% | 86.4% | 80.7% | 75% | 60.7% |
Two lessons from the table. First, a 10-point quiz barely matters: even a zero costs less than 2 points. Second, a missing 100-point project costs more than 14 points and takes an 85% (B) to 70.8% (C−). Turning in something for half credit, 50%, keeps you at 79.2%.
Missing assignments, zeros and late work
A zero is the single most damaging score in a points class because it adds possible points with nothing earned. If your teacher accepts late work with a penalty, almost any partial credit beats a zero: in the table, a 50% on a 100-point task is worth 8 more points of course grade than a missing one. Enter late penalties as the points you will actually receive.
Ungraded workLeave future assignments out of the calculator. Including them as 0/100 makes your grade look lower than the gradebook shows. To plan ahead, add the assignment with the score you expect.
From class grades to the bigger picture
Once each course grade is settled, turn the letters into a GPA with the GPA calculator, or check how a final exam will change one course with the final grade calculator. For a single test where you only know how many questions you missed, the test grade calculator is quicker. Florida’s statewide scale, for example, sets an A at 90–100 and a C at 70–79,[1] but your teacher’s syllabus is the rule that applies to you.
Frequently asked questions
How do I calculate my grade with points?
Add up all points earned, add up all points possible, divide the first by the second and multiply by 100. 159 earned out of 180 possible is 88.3%.
How do I calculate my overall grade in a class?
In a total-points class, use points earned ÷ points possible. In a weighted class, multiply each category average by its weight and add them up. Your syllabus says which one your class uses.
How much will a zero hurt my grade?
It depends on the assignment’s points compared with what is already graded. With 500 points graded at 85%, a zero on a 10-point quiz drops you to 83.3%; on a 100-point project, to 70.8%.
Why is my grade different from the average of my assignment percentages?
Because assignments with more points count more. Averaging percentages gives a 10-point quiz the same pull as a 100-point project.