Most courses split your grade into categories — homework, quizzes, a midterm, a final —
each carrying a different percentage of your total. A simple average of your scores
ignores that difference. This calculator weights each category by how much it counts,
so the final exam that's worth 35% of your grade actually pulls 35% of the weight.
Enter any number of categories·Overall grade & letter in real time·Warns when weights don't sum to 100%
Read this first
This calculator does the arithmetic correctly — but it needs the right inputs. Each row
should reflect your average score for the whole category (not a single
assignment) unless you want every individual assignment to have its own weight row.
The letter grade uses one common plus/minus scale; your school or professor may use
different cutoffs. Check your syllabus.
Add one row per grade category. Enter your score (%) and the weight (%) that category carries. Add or remove rows to match your syllabus. Results update as you type.
CategoryScore (%)Weight (%)
Overall grade
Letter grade
Total weight entered
The formulas, in full
Nothing here is a black box. These are the exact calculations the tool runs — the same
arithmetic you could do with a piece of paper and your syllabus.
overall (%) = weighted_sum ÷ total_weight
Example: 8860 ÷ 100 = 88.6%
Note: when weights sum to 100, this equals weighted_sum ÷ 100.
When weights do NOT sum to 100, dividing by their actual total
is the correct proportional calculation — not division by 100.
4 — Letter grade (common plus/minus scale; schools vary)
A ≥ 93% A− ≥ 90%
B+ ≥ 87% B ≥ 83% B− ≥ 80%
C+ ≥ 77% C ≥ 73% C− ≥ 70%
D+ ≥ 67% D ≥ 63% D− ≥ 60%
F < 60%
Standard letter-grade scale reference
The table below shows the plus/minus scale this calculator uses. It is one common
convention — your school may use whole-letter grades only, different cutoff points,
or a different threshold for an A. The scale is labeled "common scale, schools vary"
throughout this page for that reason.
Letter grade
Percentage rangecommon scale, schools vary
Typical meaning
A
93 – 100%
Excellent
A−
90 – 92%
Excellent
B+
87 – 89%
Good
B
83 – 86%
Good
B−
80 – 82%
Good
C+
77 – 79%
Satisfactory
C
73 – 76%
Satisfactory
C−
70 – 72%
Satisfactory
D+
67 – 69%
Passing, below average
D
63 – 66%
Passing, below average
D−
60 – 62%
Lowest passing grade (common scale)
F
below 60%
Failing
Cutoff percentages shown are one common convention. Many schools use A ≥ 90%, whole-letter
grades without plus/minus, or set the passing threshold at 65% or 70%. Your syllabus is
the authoritative source for the scale that applies to your grade.
Why weight matters more than score alone
The same score shift lands very differently depending on which category it's in.
Understanding why helps you direct study effort where it actually changes the number.
High-weight categories are where your grade is actually decided
If your final exam is 35% of your grade and you have 10 homework assignments at 2% each, raising a single homework score from 70% to 100% moves your overall by 0.6 points. Raising your final score by the same 30 points moves your overall by 10.5 points — more than 17 times the effect. The weight percentage tells you directly how hard each category can swing the result.
Entering an average for the category is usually the right move
Most syllabi define weight at the category level (all homework combined = 20%), not the assignment level. If you have 10 homework grades, average them first, then enter that average with the full 20% weight. Entering 10 rows each at 2% produces the same result mathematically, but averaging first is simpler and matches how professors compute it.
Weights that don't sum to 100% are a signal, not necessarily an error
If you've only completed some graded work — the midterm is done but the final hasn't happened yet — your entered weights will be below 100%. The overall grade this calculator returns is accurate for the work entered but is not a prediction of your final grade. The calculator warns you of the difference so you can decide whether to model the ungraded work with an estimated score or simply note that the grade is partial.
A low score early in a course is more recoverable than it feels
Because the overall is weighted by category, one bad quiz grade when quizzes total 20% and you're early in the semester can be substantially offset by later work in the same or heavier categories. The math doesn't care when assignments happened; it only cares about score times weight. Entering your current numbers with planned future scores lets you see whether the recovery is feasible.
How to get the most accurate result
The calculation is exact once your inputs are right. Three steps account for most
of the error people introduce.
Pull your weights directly from the syllabus
Your course syllabus lists how much each category is worth — often in a table labeled "Grading" or "Grade breakdown." Those percentages are your weights. Enter them exactly; don't estimate. If the syllabus lists "Homework: 20 points out of 100," that's a 20% weight.
Compute your category average before entering it
If your professor averages all homework scores into one homework grade, find that average first (add them, divide by count, or check your learning management system's running average). Enter that one number as the score, not each individual homework. This mirrors how professors compute it.
Check that the weight column sums to 100%
The calculator shows your total weight and warns you if it isn't 100%. If you've entered all categories and the total is off, recheck the syllabus — weights sometimes don't add up due to extra credit or rounding, and that ambiguity is worth flagging with your professor. If some work is ungraded, the total being below 100% is expected and the current grade is a partial reading.
Use "what if" scoring to model future grades
For any category not yet graded, enter your target score and its weight. The overall will update to show what you'd need from remaining work to hit a given final grade. Adjust the score on the ungraded rows to find the threshold you need on those assignments.
Where to buy
Got your numbers? Here's where to pick up what you need:
The vocabulary behind the calculation — in plain English.
Weighted grade
An overall score computed by multiplying each category's score by its share of the total grade, then dividing by the sum of those shares. Unlike a simple average, it lets some categories count more than others — so a final worth 35% has 3.5 times the pull of a category worth 10%.
Weight (category weight)
The percentage of your final grade that a given category represents. If the syllabus says "Quizzes: 20%," the weight is 20. Weights across all categories should sum to 100 when all graded work is accounted for.
Weighted sum
The intermediate result before dividing: each category's score multiplied by its weight, all added together. For the default example in this tool, that's 95×20 + 88×20 + 82×25 + 90×35 = 8,860.
Simple (unweighted) average
The mean of a set of scores — add them all, divide by the count. It treats every score equally, regardless of how much any individual item counts. A simple average of grades is only correct when every item has exactly the same weight.
Grade category
A grouping of related assignments that a professor evaluates together and assigns a single weight — for example, "Homework," "Quizzes," "Midterm," "Final." The category's weight is applied to the category's average score, not to each assignment individually.
Letter grade
A letter (A through F, sometimes with plus and minus modifiers) that translates a percentage score into a qualitative range. The boundaries between letters vary by school and professor — the scale shown on this page is one common convention, not a universal standard.
Syllabus
The course document your professor distributes at the start of term, which defines what percentage each category is worth, any extra-credit policies, and the letter-grade cutoffs in effect for that particular class. For any grading calculation, the syllabus takes precedence over any general-purpose tool.
Frequently asked
Multiply each category's score (as a percentage) by its weight percentage, add those products together, then divide by the sum of your weights. When all weights add to 100, you divide by 100 — the shortcut form. For example: Homework 95% × 20 = 1,900; Quizzes 88% × 20 = 1,760; Midterm 82% × 25 = 2,050; Final 90% × 35 = 3,150. Weighted sum = 8,860. Overall = 8,860 ÷ 100 = 88.6%. Use the calculator above with your syllabus weights and category averages to run this for your own course.
An unweighted (simple) average adds all scores and divides by the count, treating every item equally. A weighted average multiplies each score by how much it counts before summing. If your final exam is 35% of your grade but your homework — 10 assignments at 2% each — totals only 20%, the final has 3.5 times the impact of homework collectively and 17.5 times the impact of any single assignment. A simple average of all 12 things would make each item equal, which is wrong. Most college and high school courses publish a weight breakdown; this calculator uses those weights.
The calculation still gives a valid result — it divides by whatever the weights total, so the math is proportionally correct for the categories entered. A total below 100% typically means you've entered completed work but left out future categories (like a final not yet taken). The overall grade shown is accurate for the entered work; it's not a projection of your final grade. A total above 100% usually indicates a data entry error and is worth rechecking. This calculator displays your total weight and warns you when it differs from 100% so you can make an informed decision.
The impact equals the category's weight times the score difference, divided by the total weight. A rough version: if the midterm is 25% of your grade and you score 60% instead of an expected 90%, the swing is roughly 0.25 × (60 − 90) = −7.5 percentage points on your overall. You can model this directly in the calculator: enter that category's actual score, compare the overall to what you'd get with your target score, and see the difference. That is more reliable than estimating, because it accounts for all the other categories at once.
It means the entire category — all assignments within it, averaged together — counts for that share of your final grade. If homework is 20%, your professor first averages all your homework scores into a single homework average, then that average is multiplied by 0.20 (20%) in the overall calculation. This is how the rows in this calculator work: each row represents one category. Enter your average for all assignments in that category as the score, not each assignment individually — unless you want to give each assignment its own weight row, in which case set that assignment's specific weight.
Yes. Enter every completed category first. Then add a row for the final with its weight from your syllabus. Set the score to any value and watch the overall update live. Slide the final's score down until the overall hits your minimum passing threshold (for example, 70%), and that score is your minimum needed. For this to be accurate, the weights you enter must add up to exactly 100% once the final row is included; the calculator will confirm whether they do. If there are other incomplete categories besides the final, add them too with estimated or target scores.
This calculator uses a common plus/minus letter-grade scale (A ≥ 93%, A− ≥ 90%, B+ ≥ 87%, and so on down to F below 60%). This is one widely used convention, but schools vary considerably. Some use only whole-letter grades with cutoffs at 90/80/70/60; others set the A threshold at 94%; some don't use a minus for D. The full scale is shown in the grade scale reference table on this page, labeled "common scale, schools vary." Check your syllabus for the exact cutoffs your professor uses — the letter grade from this tool is an estimate, not your official grade.
Yes — weight directly determines how much a score in that category can move your overall grade. A 35% category has 3.5× the leverage of a 10% category. The same 10-point improvement in your score on the heavy category improves your overall 3.5 times as much as the same improvement in the lighter one. This is the main reason to focus study effort on high-weight assessments when exam time is limited: the return on time invested is proportional to the weight. That said, don't let low-weight categories collapse — they still count, and accumulating zeros on homework (even at 2% each) adds up across a semester.
Common mistakes with this calculator
Weighted grade arithmetic is exact — but only when the inputs match how your
professor actually computes the grade.
Entering individual assignment scores instead of the category average
Most syllabi assign weight at the category level — “Homework: 20%” means all homework grades averaged together count for 20%, not that each assignment carries its own share. If you enter ten homework rows each at 2%, the math is identical only if you have exactly ten equally-weighted assignments. The safer practice: average your homework scores first, enter that single average, and assign it the full 20% weight. That is also exactly how your professor computes it.
Letting weights sum to more or less than 100%
When weights do not sum to 100%, the calculator divides by their actual total rather than 100, giving a proportionally correct result for the categories entered — but that is not your overall course grade unless those categories represent the entire course. The weight-total indicator exists to catch this. If some categories are incomplete (final not yet taken), the partial grade is informative but not final. If all categories are entered and they still do not sum to 100%, recheck your syllabus before trusting the output.
Using the letter grade shown here when your professor uses a different scale
The letter grade this calculator shows uses one widely cited plus/minus scale (A ≥ 93%, B ≥ 83%, etc.), which is labeled “common scale, schools vary” throughout. If your syllabus sets A at 90% or uses no plus/minus bands, the letter shown here will not match your transcript. Use the percentage output — that is always correct given your inputs — and look up the letter in your own syllabus rather than relying on this calculator’s conversion.
Entering a score for a future or ungraded category
If you enter a score for the final exam before you have taken it, that score is a projection, not a measurement. The result will show your projected overall grade given that assumption — useful for “what if” planning but easily confused for an actual current grade. Make clear to yourself which rows are actual and which are hypothetical; the calculator treats all rows identically.