Weighted course grade calculator
Homework 92 at 20%, quizzes 85 at 15%, midterm 78 at 25% and final 88 at 40% give a course grade of 85.85%. Each category score is multiplied by its syllabus weight, and you see how many points every category contributed. Free in your browser.
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Most college and high-school courses do not award a single raw average of every quiz and homework set. The syllabus instead assigns each category a weight—twenty percent homework, fifteen percent quizzes, twenty-five percent midterm, forty percent final—and the official grade is the weighted combination of those category scores. This weighted course grade calculator accepts a list of named categories with a percentage score from zero to one hundred and a positive weight, multiplies each score by its weight, divides by the total weight, and returns the overall weighted percentage plus a transparent contribution breakdown for every row.
What a weighted course grade is and why equal averages mislead
A plain arithmetic mean of every assignment treats a five-point quiz the same as a hundred-point final exam. Syllabi reject that model. They group work into categories—homework, quizzes, labs, projects, midterm, final exam—and publish a weight for each category as a percentage of the course total.
If homework is twenty percent and the final is forty percent, a ninety on the final must move the course grade twice as far as a ninety on homework. The correct formula is the weighted mean: multiply each category score by its syllabus weight, sum those products, and divide by the sum of the weights. When the weights already sum to one hundred, that quotient is exactly the official course percentage.
When weights are relative units that do not sum to one hundred—for example three, two, and five—the same formula still works because dividing by the total weight normalizes them. Equal weighting is only the special case where every weight is identical; it is not the default for a graded course. Students who average raw assignment percents without category weights often overestimate or underestimate the grade the registrar will post.
Teachers who retype weights into a spreadsheet for every section risk a single wrong cell changing a letter boundary. A dedicated weighted course grade calculator encodes the syllabus contract once, returns both the overall percentage and each category contribution, and never invents a silent NaN when a weight is missing or zero.
When a syllabus-weighted grade helps most
Learning management systems and tutoring platforms use a weighted course grade calculator so learners can plug in running category averages mid-semester and see the official percentage without waiting for the instructor spreadsheet. Advisors and academic coaches recompute what-if scenarios when a student considers dropping a category or when a syllabus revision changes the final exam weight. Failed validation does not consume balance.
Keep category lists short, pin the rounded percentage and contribution fields in tests, and you get reproducible course grades for homework checkers, LMS plugins, and edge workers without standing up a full gradebook database. The capability is intentionally narrow: it computes the weighted percentage and the contribution breakdown; it does not assign letter grades, curve distributions, or drop the lowest quiz—those policies belong in the caller once the numeric percentage is known.
What you can do with it
Mid-semester running course percentage
Students enter current category averages and syllabus weights to see the official weighted course percentage before finals week.
Gradebook export verification
Instructors recompute each student weighted percentage from category rows to catch spreadsheet weight or score typos before posting grades.
FAQ
Do the weights have to sum to 100?
No. Weights that sum to 100 match a classic syllabus percent table, but any positive relative weights work because the formula divides by the total weight.
What score range is accepted?
Each category score must be a finite number from 0 to 100 inclusive.
What does the contributions array show?
Each entry echoes name, score, and weight, plus contribution equal to that category share of the overall percentage after the same half-up rounding.
Why is my weighted grade different from the average of my scores?
A plain average gives every category the same pull, but a syllabus does not. With the final at 40% and homework at 20%, each point earned on the final moves the course grade twice as far as a point on homework.
How do I test a what-if, such as dropping a category?
Remove the category or change its weight and recalculate. The scores are divided by the total of the remaining weights, so they do not need to add up to 100; relative weights such as 3, 2 and 5 work the same way.
Related tools
For developers — API access
Everything on this page is available programmatically. This section is for teams who want to wire it into their own systems; everyone else can just use the tool above.
API endpoint
Prefer to automate it? One authenticated POST creates the task; the result comes back by webhook or a signed link. The same capability also runs here on the web, by email and from Telegram — and soon from our app too.
Call it from your stack
curl -X POST https://api.kit.forhosting.com/edu/weighted-course-grade \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"categories":[{"name":"homework","score":92,"weight":20},{"name":"quizzes","score":85,"weight":15},{"name":"midterm","score":78,"weight":25},{"name":"final","score":88,"weight":40}]}'const res = await fetch("https://api.kit.forhosting.com/edu/weighted-course-grade", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"categories": [
{
"name": "homework",
"score": 92,
"weight": 20
},
{
"name": "quizzes",
"score": 85,
"weight": 15
},
{
"name": "midterm",
"score": 78,
"weight": 25
},
{
"name": "final",
"score": 88,
"weight": 40
}
]
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/edu/weighted-course-grade",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"categories": [
{
"name": "homework",
"score": 92,
"weight": 20
},
{
"name": "quizzes",
"score": 85,
"weight": 15
},
{
"name": "midterm",
"score": 78,
"weight": 25
},
{
"name": "final",
"score": 88,
"weight": 40
}
]
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/edu/weighted-course-grade", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"categories":[{"name":"homework","score":92,"weight":20},{"name":"quizzes","score":85,"weight":15},{"name":"midterm","score":78,"weight":25},{"name":"final","score":88,"weight":40}]}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"categories":[{"name":"homework","score":92,"weight":20},{"name":"quizzes","score":85,"weight":15},{"name":"midterm","score":78,"weight":25},{"name":"final","score":88,"weight":40}]}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/edu/weighted-course-grade", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"categories": [
{
"name": "homework",
"score": 92,
"weight": 20
},
{
"name": "quizzes",
"score": 85,
"weight": 15
},
{
"name": "midterm",
"score": 78,
"weight": 25
},
{
"name": "final",
"score": 88,
"weight": 40
}
]
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "edu.weighted_course_grade",
"status": "queued",
"_links": {
"result": "/tasks/tsk_…/result"
}
}The API is asynchronous: the call returns a task_id immediately and the result arrives by webhook. Polling is capped at 1 req/s per task.
Pricing
Published price — no tokens, no invented credits. A failed task is never charged.
Errors
| HTTP | Code | Meaning |
|---|---|---|
401 | unauthorized | Missing or invalid API key. |
402 | insufficient_balance | Your balance doesn't cover the task price. |
404 | unknown_type | That task type doesn't exist. |
429 | rate_limited | Too many requests. Use the webhook instead of polling. |
Technical notes
The arithmetic is fully deterministic, runs free in your browser, and is available over the API at $0.002 per successful request with no language model and no external gradebook service on the hot path.
What a weighted course grade is and why equal averages mislead
Empty category lists, blank names, scores outside zero to one hundred, and non-positive weights fail validation immediately with invalid_input so automation can distinguish bad input from a legitimate low grade.
Input contract, formula, rounding, and response shape
Each object needs three fields: name, a non-empty string label such as homework or midterm; score, a finite number from zero to one hundred inclusive representing the percentage earned in that category; and weight, a finite number strictly greater than zero representing the syllabus weight in percent points or any positive relative unit. Optional decimals is an integer from zero to six that controls half-up rounding of the overall percentage and of each contribution; the default is two decimal places so a result such as eighty-five point nine five matches common gradebook displays. Example: homework ninety-two at weight twenty, quizzes eighty-five at fifteen, midterm seventy-eight at twenty-five, and final eighty-eight at forty yields a total weight of one hundred and an overall weighted percentage of eighty-five point eight five when decimals is two. POST a JSON body with a required categories array of one to forty objects. Aliases items, components, and rows are accepted for the categories field so scripts that already speak in those terms do not need a rename step. The core walks the list once, accumulates the sum of score times weight and the sum of weights, and computes weighted_percentage equals that product sum divided by the total weight. If the total weight is zero the request fails—though every accepted weight is positive, so this path only appears if validation is bypassed. On success the body includes weighted_percentage, total_weight, categories_count, a contributions array that echoes each name, score, and weight together with that row contribution to the overall percentage, and a formula string restating the contract.
Where a syllabus-weighted grade API earns its keep
Teachers and teaching assistants batch-call the API per student to append a verified weighted column when exporting a gradebook, catching rows where a weight was left blank or a score was typed as one hundred ten.
Integration use cases
LMS and tutoring automation
Platforms call the API with homework, quiz, midterm, and final rows so plugins show the same number as the syllabus formula.
Technical questions
How is the weighted course percentage calculated?
Multiply each category score by its weight, sum those products, and divide by the sum of the weights: weighted_percentage = sum(score_i × weight_i) / sum(weight_i).
What triggers an error, and what does a call cost?
Empty categories, blank names, non-positive weights, scores outside 0–100, or missing required fields return invalid_input and are not billed. Successful API calls are priced from $0.002.