Overall grade from categories
Homework at 92, quizzes at 88, a midterm at 79 and a final at 85, weighted 20, 15, 25 and 40, give an overall of 85.35%, a B. Enter each category's average and weight to get the course percent and its letter. Free in your browser.
- Free
- Runs in your browser
- No sign-up
- Your data stays on your device
Run — free
Most syllabi do not average every quiz and homework item in one running pile. They split the term into named categories — homework, quizzes, labs, a midterm, a final project — each with its own average and a published weight. Students, teachers, and advisors who already have those category averages still need one overall course percentage and a letter they can put on a report card or transcript preview. This overall-grade-from-categories calculator takes each category average with its syllabus weight, forms the weighted mean, and maps the rounded percent onto a documented US ten-point letter scale with plus and minus bands. No curve, no remaining-work forecast, and no network call — just the overall course grade implied by the category table on the syllabus.
How category averages become one overall course percent
A category-weighted course grade is not the same as a simple average of every assignment. First each category is reduced to its own average — homework as a percent, quizzes as a percent, exams as a percent — and only then are those averages combined. The overall is the weighted mean: multiply every category average by that category’s weight, add the products to get earned points, and divide by the sum of the weights.
Homework at ninety-two with weight twenty, quizzes at eighty-eight with weight fifteen, a midterm at seventy-nine with weight twenty-five, and a final at eighty-five with weight forty produce earned points of eight thousand five hundred thirty-five and an overall of eighty-five point thirty-five percent when the weights sum to one hundred.
If the weights are any other consistent positive units — points in a pool, shares that sum to ten, or a half-finished table that does not yet add to one hundred — the same formula still holds because the total weight sits in the denominator. Extra credit that pushes a category average above one hundred is allowed and simply raises that category’s contribution. After the raw overall is computed, half-up rounding to the chosen decimal places produces the display percent that students and parents see.
The letter is then read from that rounded percent, not from the unrounded fraction, so the number on the page and the letter next to it never disagree.
Where an overall-from-categories calculator earns its keep
Students use an overall grade from categories calculator when the learning-management system shows four category averages but not the combined course mark, or when a paper syllabus is the only source of weights. Teachers close a term by pasting the same category table they published in week one and reading one percent and one letter for the gradebook, without rebuilding a spreadsheet that someone else will drift.
Academic advisors and tutoring centers need a deterministic oracle that turns a messy weight table into a single reportable overall during a short appointment. Parent portals and LMS plugins can call the same pure module from a server job or an edge worker so a “current overall” field stays consistent with the free browser check a family already ran at home. Failed validation does not consume balance.
Pin the rounded overall and letter in tests, document the letter scale beside the result, and you get a reproducible course-close helper for gradebooks, FAQ bots, and advising workflows.
What you can do with it
Syllabus mid-term check
Enter the published homework, quiz, midterm, and project weights with the averages you already have and read the current overall percent and letter before the final is graded.
Teacher gradebook close-out
Paste the same category table from the course outline, drop in each category average, and write one overall and one US letter into the official gradebook.
FAQ
How do I calculate an overall grade from weighted categories?
Multiply each category average by its weight, add those products, and divide by the sum of the weights. This tool also maps the rounded overall onto a US letter (A+ through F).
Do the category weights have to add up to 100?
No. Weights need only be positive and consistent. Percents that sum to 100, point pools, or any proportional scheme work.
What letter grade scale is used for the overall?
A common US ten-point scale with plus/minus: A+ from 97, A from 93, A- from 90, B+ from 87, B from 83, B- from 80, C+ from 77, C from 73, C- from 70, D+ from 67, D from 63, D- from 60, and F below 60. Band min and max are returned with the letter.
Can a category average be above 100 for extra credit?
Yes. Averages may be any finite number, including values above 100, so extra credit in one category raises that category’s contribution to the overall.
Which category affects my overall grade the most?
The result shows what each category adds to the overall. In the example the final, weighted 40, contributes 34 points of the 85.35, while homework at 92 adds only 18.4, so a heavy weight can matter more than a high average.
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/overall-from-categories \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"categories":[{"name":"Homework","average":92,"weight":20},{"name":"Quizzes","average":88,"weight":15},{"name":"Midterm","average":79,"weight":25},{"name":"Final","average":85,"weight":40}]}'const res = await fetch("https://api.kit.forhosting.com/edu/overall-from-categories", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"categories": [
{
"name": "Homework",
"average": 92,
"weight": 20
},
{
"name": "Quizzes",
"average": 88,
"weight": 15
},
{
"name": "Midterm",
"average": 79,
"weight": 25
},
{
"name": "Final",
"average": 85,
"weight": 40
}
]
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/edu/overall-from-categories",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"categories": [
{
"name": "Homework",
"average": 92,
"weight": 20
},
{
"name": "Quizzes",
"average": 88,
"weight": 15
},
{
"name": "Midterm",
"average": 79,
"weight": 25
},
{
"name": "Final",
"average": 85,
"weight": 40
}
]
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/edu/overall-from-categories", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"categories":[{"name":"Homework","average":92,"weight":20},{"name":"Quizzes","average":88,"weight":15},{"name":"Midterm","average":79,"weight":25},{"name":"Final","average":85,"weight":40}]}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"categories":[{"name":"Homework","average":92,"weight":20},{"name":"Quizzes","average":88,"weight":15},{"name":"Midterm","average":79,"weight":25},{"name":"Final","average":85,"weight":40}]}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/edu/overall-from-categories", 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",
"average": 92,
"weight": 20
},
{
"name": "Quizzes",
"average": 88,
"weight": 15
},
{
"name": "Midterm",
"average": 79,
"weight": 25
},
{
"name": "Final",
"average": 85,
"weight": 40
}
]
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "edu.overall_from_categories",
"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.
Limits
max_items | 40 |
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
Input contract, letter bands, and validation
Each record needs a finite average and a strictly positive weight. Optional name (or category, or label) is a short string used in the contribution rows; blank or omitted names are dropped from the output rather than filled with a placeholder. Optional decimals is an integer from zero through six and defaults to two; it controls half-up rounding of the overall, the echoed weights, and each contribution. Letter bands follow a common US ten-point scale: A-plus from ninety-seven, A from ninety-three, A-minus from ninety, then B, C, and D with plus and minus steps, and F below sixty. Send a JSON object whose required categories field is an array of at least two and at most forty records. Average also accepts the aliases score, percent, and pct so thin clients can reuse familiar field names. The whole list accepts items or rows as aliases for categories. On success the body returns category_count, total_weight, earned_points as the raw weighted sum, overall as the rounded percent, percent_label, letter_grade, band_min and band_max for that letter, a passing flag that is true at sixty percent or above, weights_sum_to_100 so you can see whether the syllabus table closed, a contributions array with average, weight, share of the course, and contribution to the overall, plus formula, scale, decimals, and a short message for UI copy. Missing categories, fewer than two rows, more than forty rows, a non-positive weight, a non-numeric average, or decimals outside zero through six throw invalid_input and are not billed.
Integration use cases
Advisor and parent-portal display
Turn unofficial category averages from a portal export into a stable overall and letter that matches the free browser widget families already used at home.
Technical questions
What does the overall grade from categories calculator cost?
The browser tool is free. API requests use prepaid KIT balance at $0.002 per successful call; invalid input is not billed.