Grade calculator
Free grade calculator for weighted percentage scores. Check contributions and weights totaling 100%, compare exam scenarios and avoid common grading errors.
By Calcr · Updated
Grade calculator: Enter scores and their weights
Enter between 1 and 30 scores as percentages from 0 to 100 and the weight each contributes to the final result. Weights must be positive and total 100%. A blank score needs attention; it is not silently converted into a zero.
Weighted-grade formula
Final percentage = (score 1 * weight 1 + score 2 * weight 2 + ...) / 100. The weight belongs to the component, not to its raw number of points. Convert 18 points out of 20 to 90% before entering it.
Worked examples
Two components: coursework at 80% with weight 40% contributes 32 points. An exam at 90% with weight 60% contributes 54. The final result is 86%.
Three components: 75% at 20%, 84% at 30% and 92% at 50% give 15 + 25.2 + 46 = 86.2%.
Equal weights: scores of 60% and 100% at 50% each produce 80%. Their arithmetic mean happens to match because the weights are equal.
Limits
Use the weights in your syllabus. This calculator does not infer letter grades, GPA, extra-credit policy, dropped assessments or a school's treatment of unfinished work. It rejects incomplete totals instead of assuming the missing weight. A calculation is an estimate, not an official academic record.
When to use this weighted grade calculator
Use this free grade calculator when your course expresses each component as a percentage score and assigns it a percentage weight. It can check a completed course result or compare clearly labelled hypothetical scores. Gather the syllabus weights and convert each assessment's earned points to a percentage before entering it. The calculation works from those supplied values; it does not retrieve a school's grading policy.
Keep the level of the weights consistent. If quizzes make up 20% of the course, the individual quiz weights inside that category may need to be combined before you enter the category score. Do not enter a quiz's internal weight as though it were its share of the entire course. A component can contribute fewer final percentage points than its own score because its weight is only one part of the final result.
Do not use this tool to infer a GPA, an institution's letter grade or an official pass decision. Those may depend on grade boundaries, minimum exam requirements, attendance rules or rounding policies that are absent from the arithmetic. Extra credit above 100% is also outside this form's supported score range. If an institutional calculator disagrees, compare the inputs and policy rather than assuming one decimal result settles the issue.
Example: converting points before applying weights
A project earns 36 of 40 points and has a course weight of 25%. The project percentage is 36 / 40 * 100 = 90%. An exam earns 68 of 80 points, or 85%, and has a weight of 75%. Enter scores of 90 and 85 with weights of 25 and 75. Their contributions are 22.5 and 63.75 final percentage points, producing a weighted result of 86.25%.
Entering raw scores of 36 and 68 would incorrectly treat them as percentages out of 100. Adding earned points and dividing by all possible points would give 104 / 120 * 100, approximately 86.67%, which describes a points-based scheme rather than the stated 25%/75% scheme. Either system can exist in a course, so use the one specified by your syllabus. The weighted calculator does not choose between them automatically.
Example: checking a hypothetical final examination
Suppose completed coursework has a score of 88% and is worth 70% of the course. The final exam is worth 30%. Testing an exam score of 75% gives 88 * 0.70 + 75 * 0.30 = 84.1%. Testing 90% gives 61.6 + 27 = 88.6%. Changing only the exam input makes the comparison clear, while all weights still total 100%.
If you want to find the exam score required for a target, rearrange the equation separately. A target of 85% requires (85 - 61.6) / 0.30 = 78% on the exam. Entering 78 in the exam row checks that the result is 85%. This is a scenario, not a prediction of your performance. It also assumes there is no separate minimum exam mark or other course rule.
For an unfinished course, do not silently type zero for every future assignment. A zero is a specific assumed score and can make a hypothetical final result look like a current official grade. If the school's current grade excludes ungraded work, its calculation may renormalize the completed weights. This tool instead requires a complete 100% setup. Either enter explicitly hypothetical future scores or calculate the completed portion separately with its policy stated. Keep a copy of the weights and assumptions alongside the answer.
Check the sum of the weights before examining the final percentage. Weights of 20, 30 and 40 total 90%, leaving part of the course unspecified; the tool rejects that setup rather than guessing the remaining component. A single assessment can have a weight of 100%, but every entered weight must be positive. If a course drops one assessment, first determine how the remaining weights are redistributed under its rules. Removing the row without revising the weights can leave a different grading model. Record any hypothetical score clearly so it cannot be mistaken for an earned mark.
FAQ
Why do my weights need to add to 100%?
They must describe the complete result for this calculation. The tool does not automatically renormalize them.
Can I enter points instead of percentages?
Convert earned points / possible points * 100 first.
Should an ungraded assignment be zero?
Only if your course explicitly treats it that way. A missing score and an earned zero are different.
Why does a high score add only a few points to the final result?
Its contribution depends on its course weight. A score of 100% on a quiz worth 5% contributes five final percentage points. A score of 80% on an exam worth 50% contributes forty. Compare contributions rather than scores alone when checking which assessments affect the total most. The result remains a percentage of the complete course, not a sum of raw assessment marks.
Should I round every assessment before calculating?
Use the score precision and rounding policy specified by the course. When no intermediate rounding is required, retaining the supplied decimals until the final calculation avoids accumulating avoidable rounding differences. A mathematical result of 89.95% does not automatically become a particular letter grade; a school may round, truncate or apply a boundary directly. Verify that rule with the official course documentation before interpreting a borderline result.