Grade Calculator

How to use this calculator

Choose what you want to work out with the Calculate options at the top of the form. The fields below change to match.

• Grade from exam score: type the marks you scored and the maximum possible. You get the percentage and the letter grade it usually corresponds to.
• Course grade from grades: list each grade you have received, as a percentage or a letter, and optionally the weight of each. You get the combined score, letter and GPA, plus the weight still to come and, if you set a goal, the score needed on the remaining work.
• How a grade affects a course grade: type a new exam or assignment grade and your current course grade, along with either the weight of the new grade or the number of equal grades behind the current one. You get the new course grade.

Every grade field accepts a percentage (84, 84.5) or a letter grade from A+ to F, with an optional plus or minus in capitals.

Turning an exam score into a grade

percentage = scored ÷ out of × 100

Example: 43 marks out of 50 is 43 ÷ 50 × 100 = 86%, which is a B on the usual scale. A score of 38 out of 45 gives 84.44%, also a B. The score cannot exceed the maximum, and the maximum cannot be zero.

Letter grades come from the table below, which is the most common US convention. The calculator assigns a score to the first band whose top it does not exceed, so 86% is still a B while 86.05% already counts as a B+.

Calculating a course grade

When every graded item counts equally, the course grade is the plain average. When items count for different shares, each grade is multiplied by its weight and the total is divided by the sum of the weights.

weighted grade = Σ (grade × weight) ÷ Σ weight

Unweighted example: four grades of 78, 85, 91 and 66 average to (78 + 85 + 91 + 66) ÷ 4 = 80%. You can also mix letters: A-, B+ and B are read as 92, 89 and 86, which average to 89%.

If you leave all the weight boxes empty the calculator warns you that it assumed equal weights. Enter a weight for every item to get a weighted result.

Weighted example: homework is 88% and worth 20% of the course, quizzes average 76% and are worth 15%, and the midterm is 82% and worth 25%. The weights add up to 60, so the weighted score is (88 × 20 + 76 × 15 + 82 × 25) ÷ 60 = 4,950 ÷ 60 = 82.5%. The remaining weight is 100 − 60 = 40%.

The weights may not add up to more than 100. If they do, the tool reports the sum instead of a grade. Weights below 100 are fine: they leave room for later assessments, and the amount left over appears as Weight remaining.

Setting a goal for the final

Fill in Final grade goal and the calculator treats the remaining weight as one last assessment. It solves for the score that lifts your overall result to the goal:

needed = (goal − current × (1 − r)) ÷ rcurrent is the weighted score so far, r is the remaining weight as a decimal.

Continuing the example above, a goal of 85% with 40% of the course left requires (85 − 82.5 × 0.60) ÷ 0.40 = 35.5 ÷ 0.40 = 88.75% on the remaining work. When the answer is over 100% the calculator tells you the goal is impossible. For a stand-alone version of this calculation, see the final grade calculator.

How one grade changes your average

This mode answers questions like "how much will a 72 on the next exam hurt a grade of 88?". You supply the new grade, your current course grade, and one of two extra facts.

• The new grade has a known weight w. The new course grade is current × (1 − w) + new × w. A 72 worth 25% on top of an 88 gives 88 × 0.75 + 72 × 0.25 = 84%.
• The current grade is made of n equal grades. The new grade simply joins the average: (current × n + new) ÷ (n + 1). Five equal grades averaging 92.5 plus a new B (read as 86) give (92.5 × 5 + 86) ÷ 6 = 91.42%.

If you give both the weight and the count, the weight is used. If you give neither, the calculator asks for one of them.

About the GPA shown

In the course-grade mode the GPA line is a straight-line approximation: the score minus 55, divided by 10, held between 0 and 4.3 (the top of the scale in the table above). That makes 88% a 3.30 and 82.5% a 2.75, while 99% shows 4.30 and anything at or below 55% shows 0. It is only a guide. For a figure that matches your school's official table, enter your courses in the GPA calculator, where each letter has a fixed number of grade points and each course carries credits.

The letter grades and GPA are conventional estimates. Your institution's own grading policy always decides your official result.