Grade Calculator

What a grade calculator does

A grade calculator answers two related questions about a single class.

• What is my current grade, given the scores I have so far and how much each category is worth.
• What do I need on the remaining work, usually the final exam, to finish with the grade I want.

This is different from a GPA. A class grade is the percentage or letter you earn in one course. A GPA is an average of letter grades across several courses, weighted by credit hours. If you want to combine results from many classes, use the interactive GPA calculator and its sibling pages. If you want to know where you stand inside one course right now, this is the page you want.

Most classes do not average all scores equally. Instead the syllabus assigns each category a weight, such as homework 20 percent, quizzes 20 percent, midterm 25 percent, and final 35 percent. The weights are what make the math more involved than a simple average, and they are the heart of every grade calculator.

The weighted grade formula

A weighted grade is the sum of each category average multiplied by that category weight, divided by the total weight that has been graded so far.

Grade = (sum of category average times category weight) divided by (sum of weights counted)

Write each weight as a decimal (20 percent becomes 0.20) or as a whole-number percent, just stay consistent. Steps:

1. Find your average within each category. For homework, average all your homework scores as percentages. 2. Multiply each category average by its weight. 3. Add those products together. 4. Divide by the total of the weights you included. If every category has a grade, the weights sum to 1.00 (or 100 percent) and you can skip the division.

The division step matters early in a term. If only homework and quizzes are graded so far, you divide by the weight of those two categories, not by 100 percent. That gives you your true current standing in the work completed, rather than treating ungraded categories as zeros.

Worked example: current class grade

Suppose your syllabus weights are homework 20 percent, quizzes 20 percent, midterm 25 percent, and final exam 35 percent. So far you have these category averages.

• Homework average: 92
• Quiz average: 85
• Midterm: 78
• Final exam: not taken yet

Multiply each completed category by its weight.

• Homework: 92 times 0.20 = 18.4
• Quizzes: 85 times 0.20 = 17.0
• Midterm: 78 times 0.25 = 19.5

Add the products: 18.4 + 17.0 + 19.5 = 54.9

Add the weights counted: 0.20 + 0.20 + 0.25 = 0.65

Divide: 54.9 divided by 0.65 = 84.5

Your current grade on graded work is about 84.5 percent, a solid B. The final exam, worth 35 percent, has not happened yet, so it is correctly left out of both the top and bottom of the calculation.

What you need on the final exam

To find the score you need on the final to reach a target overall grade, rearrange the formula. Let the final exam weight be w (as a decimal) and let your earned points so far be the sum of each completed category average times its weight.

Needed final score = (Target grade minus points already earned) divided by w

Where points already earned = sum of (each completed category average times its weight), using the full weights as they appear on the syllabus.

Worked example, continuing from above. Target overall grade is 90. Final exam weight is 0.35.

Points earned so far:

• Homework: 92 times 0.20 = 18.4
• Quizzes: 85 times 0.20 = 17.0
• Midterm: 78 times 0.25 = 19.5
• Total earned = 54.9

Needed final = (90 minus 54.9) divided by 0.35 = 35.1 divided by 0.35 = 100.3

That result is above 100, which means a 90 overall is out of reach unless extra credit exists. Lower the target to see what is realistic. For an 85 overall: (85 minus 54.9) divided by 0.35 = 30.1 divided by 0.35 = 86. You would need about 86 on the final to finish with an 85 in the class.

A quick reading guide for any needed-score result:

• Result at or below 60: you can pass with little risk.
• Result between 70 and 100: achievable but requires real preparation.
• Result above 100: not possible with normal scoring, adjust your target.

Points-based classes instead of percentages

Some courses do not use category weights at all. Instead every assignment is worth a fixed number of points and your grade is total points earned divided by total points possible.

Grade = (points earned) divided by (points possible so far)

Example. You have earned 540 points out of 600 possible to date.

540 divided by 600 = 0.90, which is 90 percent.

To find what you need on a remaining final worth 200 points to reach a target, use total points. If the whole course is 800 points and you want an overall 88 percent, you need 0.88 times 800 = 704 points total. You already have 540, so you need 704 minus 540 = 164 points on the 200-point final, which is 82 percent.

Check your syllabus to see which system your class uses. A points-based class and a weighted-category class can give different results from the same raw scores, so applying the wrong model is a common mistake.

From class grade to letter grade

Once you have a percentage, schools convert it to a letter using cutoffs. These cutoffs are a common convention, not a universal rule, so confirm yours from the syllabus.

The third column shows how that letter feeds into a GPA. On the standard 4.0 scale an A is 4.0, B is 3.0, C is 2.0, D is 1.0, and F is 0.0, with plus and minus values like A- at 3.7 and B+ at 3.3. Weighted GPA scales add a bonus for harder courses, commonly +0.5 for Honors and +1.0 for AP or IB, which is why a weighted GPA can rise above 4.0. To turn this single class grade into a full GPA across courses, use the interactive GPA calculator: it multiplies each course grade by its credit hours, sums those quality points, and divides by total credits.

Why grades vary between schools

Grade and GPA math looks exact, but the inputs are set locally and they differ.

• Percentage cutoffs vary. One school marks 90 as an A-, another marks 90 as a straight A. A few use a 10-point scale with no minus grades at all.
• Category weights vary by instructor, even within the same department, and sometimes change after the syllabus is posted.
• Rounding rules differ. Some classes round 89.5 up to an A-, others do not round at all.
• Colleges often recalculate GPA their own way for admissions, dropping or reweighting certain courses.
• GPA to percentage conversions are approximate. There is no official table that maps a 3.5 GPA to an exact percentage, because the underlying cutoffs were never standardized.

Treat any calculator, including this one, as a faithful model of the formula, not as the final word from your registrar. When a grade matters for eligibility, a scholarship, or a transcript, confirm the exact weights and cutoffs with your instructor or school. For combining grades across courses, the GPA calculator and the weighted GPA and GPA to percentage pages cover the cross-course math in more depth.

Frequently asked questions