Grade Calculator

How your grade is weighted

Most courses do not treat every assignment equally. A ten-minute reading quiz and a three-hour final exam both produce a score, but they rarely count the same amount toward the grade printed at the end of the term. A weight is simply the share of the final grade a single item is worth, usually written as a percentage. When an instructor says “homework is 20%, midterms are 30%, and the final is 50%,” those three numbers are weights, and they are expected to add up to 100% across the whole course.

The arithmetic behind the overall percentage is a weighted average: convert each item to its own percentage (score obtained divided by the max possible score), multiply that percentage by the item’s weight, add all of those weighted contributions together, and divide by the total weight in play. Dividing by the total weight, rather than by a fixed 100, is what lets this calculator keep working correctly even midway through a term, when you have only entered the items graded so far and their weights understandably do not reach 100% yet.

A worked example. Suppose a course has three graded items so far: a quiz average of 80 out of 100 worth 30% of the grade, a midterm of 90 out of 100 worth 50%, and a participation score of 70 out of 100 worth 20%. Each item’s percentage is multiplied by its weight: 80% × 30 = 24, 90% × 50 = 45, and 70% × 20 = 14. Adding those gives 83, and because the three weights already sum to 100, the overall grade is 83.00%, which lands in the B band on the illustrative scale below. If a fourth item worth 10% were added later, the total weight in play would grow to 110%, and the calculator would divide by 110 instead of 100 to keep the answer honest.

Reading the letter grade

The letter grade this tool shows is a generic, illustrative scale, deliberately not tied to any specific school, college or country. It exists so a bare number like “83.00%” has some familiar shorthand attached to it, in roughly the shape most people expect: A grades in the low-to-high 90s and up, B grades in the low-to-high 80s, and so on down to an F below 60%. Real institutions vary this considerably: some draw the line between a B+ and an A- a few points higher or lower, some do not use plus and minus grades at all, and some apply a curve that shifts every boundary after the fact. If your syllabus publishes its own scale, that published scale is the one that actually determines your grade, and this tool’s letter should be read only as a rough, general-purpose reference point next to it.

To go from percentage to letter grade by hand, find the overall figure in the grading scale chart below, which is the same illustrative scale the tool applies. Treat it as a reference only: a school that uses different cutoffs, or that rounds 89.5 up, will record a different letter for the same percentage.

Updating it as the term goes on

The calculator is built to be reopened, not filled in once. Add a row the moment a new score is posted, whether that is a quiz handed back in class or a grade appearing in an online portal, then press Calculate again to see the updated overall percentage and letter grade. Because the arithmetic divides by whatever weights you have actually entered rather than by a fixed 100, an incomplete list from early in the term and a complete list from the last week of classes both produce a mathematically correct answer for the items entered so far. What changes is only how much that answer can still move: a grade built from two items can shift a great deal once six more are added, while a grade built from eleven of a course’s twelve graded items is close to final.

This also makes the tool useful for planning ahead of a grade you have not received yet. Enter every item already graded, then add one more row with your best guess at an upcoming assignment’s likely score and its published weight, to see roughly how much that single item can move the overall percentage. That is an estimate rather than a guarantee, since the actual score is still unknown, but it is often enough to tell whether an upcoming test is worth an extra evening of study or is too small a share of the grade to change much either way.

Who uses a grade calculator, and for what

A grade calculator is most often used as a class grade calculator or a course grade calculator: a student types in what the gradebook already shows and checks the running total. The same arithmetic works as a high school grade calculator for a term that mixes homework, tests and a final, as a college grade calculator for a syllabus built around a paper and two exams, and as a semester grade calculator when you repeat it once per course. Teachers use it the other way round, as a quick sanity check on a category split before the syllabus is published. Because the maths is a plain weighted average, a test grade calculator and a quiz grade calculator are the same tool with different rows filled in, and a single row is enough when all you want is one test's percentage.

Category weights or total points

Courses report grades in two common ways, and the tool handles both. In a category weighted grade calculator setup, the syllabus gives each category a share, such as homework 20% and exams 50%, so you enter one row per category with its average as the score and its share as the weight. In a points based grade calculator setup, every assignment simply adds points to one running total, so you enter each item's points obtained and points possible and set each weight to that item's points possible. Either way you are using a grade calculator with weights, and the percentage it returns matches the course's own as long as the weights mirror how the course really counts each item. A points grade calculator is therefore a special case of the same weighted average, not a different method.

How to calculate your grade in a class without a tool

To check the tool, or to work without it, the method is short. For how to calculate grade percentage on a single item, divide the points obtained by the points possible and multiply by 100. For how to calculate grades across several items, multiply each item's percentage by its weight, add the results and divide by the total weight. That is also how to calculate your grade in a class at any point in the term, whether or not every item has been graded yet. Compare your answer with the tool's, and any gap almost always traces back to a mistyped weight or max score.

Running what-if scenarios

Because the list is editable, the tool doubles as a what if grade calculator. Enter the grades you have for a current grade calculator view, then add a row for an upcoming assignment with an imagined score and watch how the overall grade calculator result moves. Try a perfect score, an average one and a zero to see the range that one item can still produce. Two rule variations are worth modelling by hand. For a grade calculator with extra credit, add the bonus as its own row, as described in the FAQ below. For a drop lowest grade calculator, delete the lowest quiz row before you press Calculate, since a zero left in the list still counts. And if you only want to calculate my grade as it stands today, leave the list alone and read the result.

Names, scope and limits

People look for this tool under many names: a weighted grade calculator, a weighted average grade calculator, a grade percentage calculator, a percentage grade calculator, a grade average calculator, or just a grades calculator. They all describe the same operation, a weighted average of percentages. This one is a free grade calculator that runs as an online grade calculator in your browser with no account, and its letter grade calculator output is an illustration rather than an official mark. It does not know your school's rounding rules, cutoffs, curve or drop policy, so check any result that matters against the syllabus your instructor published.

Common mistakes

• Weights that do not sum to 100%. This is expected partway through a term when not every item has been graded yet, but it is worth double-checking near the end of a course. If the total is meant to be 100% and it is not, an item’s weight was probably mistyped.
• Forgetting extra credit. Bonus points do not always fit neatly into a “score out of max” pair. A common way to model them here is to add a separate row for the extra credit item, with the points earned as the score, a small max score matching how many bonus points were offered, and a weight matching how the syllabus counts it.
• Mixing raw points with percentages. If one assignment is out of 25 points and another is out of 200, entering the raw points obtained against the correct max score for each item keeps the percentages comparable. Entering both as if they were out of 100 will quietly produce the wrong answer.
• Dropping the lowest score without accounting for it. Some courses drop a student’s lowest quiz or homework grade automatically. If that policy applies, leave the dropped item out of the list entirely rather than entering it with a zero, since a zero still counts toward the weighted average here.