How to Calculate Grades
Every grade is either a weighted average or points earned divided by points possible. Learn both manual methods with hand-worked examples you can follow line by line.
This guide explains how to calculate grades the way teachers do: with the actual arithmetic behind the percentages. Whether your course uses weighted categories (homework 20%, exams 50%) or total points (847 out of 1,000), the math is straightforward once you see which system you are in. Work through the examples below with a pencil, and you will be able to check any grade yourself.
The calculator below runs the same math instantly. Use it to check your hand calculations, or read on to learn how to calculate grades from scratch.
Course Grade Calculator
Add your categories (weighted) or assignments (points-based) and get your current grade.
Weights should add up to 100%.
Final Exam Grade Needed
What do you need on the final to hit your target grade?
If your final has two parts and you already took part 1, fill both fields and we will tell you what part 2 needs.
What-If Scenario
See how a future score changes your grade before it happens.
GPA Calculator
Semester or cumulative GPA — weighted or unweighted.
Scale: A/A+ = 4.0, A- = 3.7, B+ = 3.3, B = 3.0, B- = 2.7, C+ = 2.3, C = 2.0, C- = 1.7, D+ = 1.3, D = 1.0, D- = 0.7, F = 0.
Quick Quiz Grader
For students checking a score — and teachers grading a stack.
Grade Calculator for Your LMS
Each platform grades a little differently. Pick yours — we'll load the right setup into the Course Grade calculator.
Canvas
Uses assignment groups with weights (e.g. Homework 30%, Quizzes 20%, Exams 50%). Matches the Weighted mode.
Blackboard
Weighted totals per category. Same math as Canvas — categories with percentage weights.
Moodle
Gradebook aggregates by mean of grades, often points-based with categories. Start points-based.
Google Classroom
Simple points-based gradebook. Start points-based and enter your scores.
After loading a setup, open the Course Grade tab — your categories are pre-filled. Just enter your scores.
The two systems: weighted vs points-based
Before calculating anything, identify which system your course uses. It is always stated in the syllabus, usually near the top.
Weighted grading assigns each category a percentage weight: homework 20%, quizzes 20%, midterm 25%, final 35%. Your grade is the weighted average of your category scores. This is the most common system in high school and college.
Points-based grading skips categories. Every assignment is worth a number of points, and your grade is total points earned divided by total points possible. A 1,000-point course where you earned 847 points gives 84.7%.
Knowing which system applies is half the battle. The most common beginner error in learning how to calculate grades is mixing the two: entering raw point scores into a weighted formula, or vice versa.
How to calculate grades with weighted categories
Convert each category score to a percentage, multiply by its weight as a decimal, and add the results. The weights must add to 100% (or 1.0 as decimals).
Worked example. Your syllabus weights homework at 20%, quizzes at 20%, the midterm at 25%, and the final at 35%. Your scores: homework 90%, quizzes 84%, midterm 76%, final 88%.
- Homework: 90 x 0.20 = 18.0
- Quizzes: 84 x 0.20 = 16.8
- Midterm: 76 x 0.25 = 19.0
- Final: 88 x 0.35 = 30.8
Add them: 18.0 + 16.8 + 19.0 + 30.8 = 84.6. Your course grade is 84.6%, a B on the common grading scale chart. Notice the final exam contributed 30.8 points, more than any other category, because its 35% weight amplifies every point earned or lost there.
A useful check: if all your category scores were identical, say 85% everywhere, the weighted average must equal 85%. If your calculation gives anything else, recheck the weights.
How to calculate grades with total points
This method is simpler. Add up every point you earned, add up every point possible, and divide.
Worked example. Across the semester you earned: homework 180/200, quizzes 160/200, midterm 152/200, final 176/200, participation 95/100, project 84/100. Total earned = 180 + 160 + 152 + 176 + 95 + 84 = 847. Total possible = 200 + 200 + 200 + 200 + 100 + 100 = 1,000. Grade = 847 / 1,000 x 100 = 84.7%.
In points-based systems, every point is equal: a point from a 10-point homework moves your grade exactly as much as a point from a 200-point final. That also means small assignments add up. Ten missed 5-point homeworks cost 50 points, the same as bombing half of a 100-point exam.
To convert a single assignment to a percentage first (useful when mixing with weighted math): divide earned by possible and multiply by 100. A 42/50 assignment is 42 / 50 x 100 = 84%.
How to calculate grades when scores are dropped
Many syllabi drop the lowest score in a category ("lowest quiz dropped"). The rule: remove the dropped score from both your inputs and the category average entirely, as if it never existed.
Worked example. Quiz scores: 70, 85, 92, 78. The syllabus drops the lowest quiz. Remove the 70. Average the rest: (85 + 92 + 78) / 3 = 255 / 3 = 85.0% for the quiz category. If you had wrongly included the 70, the average would be (70 + 85 + 92 + 78) / 4 = 325 / 4 = 81.25%, understating your grade by nearly 4 points.
In a points-based course, dropping works the same way: subtract the dropped assignment's earned and possible points from your totals before dividing. If a 20-point quiz is dropped, remove both the points you earned on it and the 20 from the possible total.
Common trap: some courses drop the lowest score only within a category, not across the whole course. A dropped quiz does not rescue a bad midterm. Read the syllabus line carefully.
Extra credit: how it fits the math
Extra credit usually adds earned points without adding possible points, which is what makes it powerful. Worked example. You earned 820 of 1,000 regular points (82.0%), plus 15 extra credit points. New total: 835 earned out of 1,000 possible = 835 / 1,000 x 100 = 83.5%. Those 15 points lifted the grade by 1.5 percentage points.
In a weighted course, extra credit is normally added to a specific category (often homework or participation). Add the extra points to that category's earned total before computing its percentage, then proceed with the weighted average as usual. If the syllabus is vague about where extra credit lands, ask: the same 15 points can be worth more in a lightly weighted category than a heavy one, or vice versa, depending on the category's size.
Curved grades: what changes in the calculation
A curve adjusts raw scores before the normal math applies. The most common college curve adds a fixed number of points to everyone's score. Example: your raw midterm average is 78%, and the professor adds 7 points to all scores. Your curved midterm is 85%, and that 85% is what enters the weighted average.
Another common curve sets the top score to 100% and shifts everyone up by the same amount. If the highest exam score was 88, everyone gets +12. Your 78 becomes 90. The key point for hand calculation: apply the curve to the individual scores first, then run the standard weighted or points math on the curved numbers.
Because curves are announced late (sometimes after finals), early-semester hand calculations should use raw scores, with a note that a curve may lift the final result. Never assume a curve is coming.
Common mistakes when calculating grades by hand
Weights that do not sum to 100%. If your syllabus lists homework 20%, quizzes 20%, midterm 25%, and final 30%, that totals 95%. The missing 5% is usually participation or attendance. Find it before calculating, or every result will be wrong.
Averaging percentages instead of weighting them. With categories worth different amounts, a straight average of your category percentages is wrong. A 90% in a 10%-weighted category and a 70% in a 50%-weighted category do not average to 80%.
Forgetting that zeros count. A missing assignment entered as zero still counts in the average (unless the syllabus drops it). Students estimating "my grade if I skip this" often delete the assignment from the math entirely, which overstates the result. The correct move: include it as zero, or check what the syllabus says about missing work.
Rounding mid-calculation. Keep one or two extra decimals through every step and round only the final percentage. Early rounding across five categories can shift the answer by a few tenths, which matters near letter-grade boundaries.
Using the wrong scale for the final letter. An 89.5% is an A- on some scales and a B+ on others. The percentage math is universal, but the letter it maps to depends on your school. Confirm with the grading scale chart your course actually uses.
Putting it together: a full-semester example
The best way to master how to calculate grades is one example that combines everything: weights, dropped scores, and multiple categories. Take this syllabus: homework 25% (lowest dropped), quizzes 25% (lowest dropped), midterm 20%, final 30%.
- Homework scores: 95, 88, 92, 76. Drop the 76. Category average: (95 + 88 + 92) / 3 = 275 / 3 = 91.67%.
- Quiz scores: 80, 85, 90, 70. Drop the 70. Category average: (80 + 85 + 90) / 3 = 255 / 3 = 85.0%.
- Midterm: 82%. Final: 88%.
Now weight each category: homework 91.67 x 0.25 = 22.92, quizzes 85.0 x 0.25 = 21.25, midterm 82 x 0.20 = 16.40, final 88 x 0.30 = 26.40. Add them: 22.92 + 21.25 + 16.40 + 26.40 = 86.97, which rounds to 87.0%, a B+. If you can follow this example line by line, you know how to calculate grades in any system a syllabus throws at you.
From grades to GPA
Once you can calculate a course grade, the next step is combining courses into a GPA: convert each final letter grade to grade points, multiply by credit hours, and divide by total credits. Our step-by-step guide on how to calculate GPA walks through that math with worked examples. And if you are wondering whether your numbers are competitive, see what counts as a good GPA.
How to calculate grades: FAQs
What is the basic formula to calculate a grade?
For weighted courses: multiply each category percentage by its weight as a decimal and add the results. For points-based courses: divide total points earned by total points possible and multiply by 100. Identify your system from the syllabus first.
How do I calculate my grade if weights do not add to 100%?
Find the missing weight before calculating, usually participation, attendance, or a small category hiding in the syllabus. If the weights genuinely do not sum to 100% and nothing is missing, ask your instructor which total the course uses, because the math depends on it.
How do dropped scores affect grade calculation?
Remove the dropped score completely: from the category average in weighted systems, or from both earned and possible totals in points-based systems. A dropped 70 among quiz scores of 85, 92, and 78 leaves (85 + 92 + 78) / 3 = 85.0% instead of 81.25%.
How is extra credit calculated?
Extra credit typically adds to points earned without increasing points possible. Example: 820 earned + 15 extra credit out of 1,000 possible = 835 / 1,000 = 83.5%. In weighted courses, add it to the category the syllabus assigns it to.
Why does my calculated grade differ from the online gradebook?
The usual causes: a category the teacher has not published yet, a dropped score you did not remove, weights that do not sum to 100%, or a grading scale different from the one you assumed. Compare your inputs against the syllabus line by line.
How do I calculate what I need on the final exam?
Use the formula: needed score = (target grade - current grade x (1 - final weight)) / final weight, with the weight as a decimal. Example: current 84%, target 90%, final worth 25%: (90 - 84 x 0.75) / 0.25 = (90 - 63) / 0.25 = 108%, which is out of reach without extra credit.
Do all teachers calculate grades the same way?
No. Teachers choose weighted or points-based systems, set their own category weights, and decide policies on dropped scores, extra credit, and curves. The arithmetic methods in this guide work for every system, but the inputs always come from your specific syllabus.