About Gradely
Gradely is a set of five grade calculators that run entirely in your browser. There is no account, no server that receives your scores, and no step where anything you type leaves your device. It exists because the arithmetic behind a grade is simple, the policy around a grade is not, and most calculators quietly blur the two — printing a letter as though it were a fact rather than a local rule.
The two methods, and why we show both
A course grade is computed one of two ways. Weighted categories assign a share of the final grade to each kind of work and average the category percentages by those shares. Total points pools every assignment and divides points earned by points available. Given the same scores these produce different answers whenever a category's weight differs from its share of the available points, and the gap is routinely several percentage points and sometimes a letter. The grade calculator lets you switch between them on the same data, because the first thing you need to know about your course is which one it uses.
Rounding, stated once
Percentages are displayed to two decimal places on the calculators and to one on the reference charts, always rounded half-up. Letter grades are assigned from the exact unrounded value unless you tick the rounding box, which rounds to a whole percent first. That checkbox exists because whether 89.5 becomes an A is your instructor's decision and not a mathematical one, and a calculator that silently picks a side is lying to you about which kind of question it is.
Under the surface, all rounding goes through one function that first normalises the value to twelve significant figures. Without that step binary floating point turns 23 ÷ 80 into 28.749999999999996 and a naive rounding call reports 28.7 for a number that is exactly 28.75. Small, but it is exactly the kind of error that makes a table disagree with the tool printed above it.
Why every scale here says "common"
Grading scales are set by institutions. There is no national standard in the United States for where an A begins, whether plus and minus grades exist, what an A+ is worth in grade points, or whether a semester percentage is rounded before it becomes a letter. Ten-point bands are the arrangement most people have in mind, but a student can just as easily land in a school using seven-point bands, and we are not in a position to tell you which one you are in. So this site shows three scales side by side, labels each of them a common arrangement rather than a standard, and repeats that caveat next to the numbers on every page instead of burying it in a footer. Of the 22 percentages in the comparison table on the home page, 12 get a different letter depending only on which scale is in force.
The same applies to grade points. The 4.0 plus/minus values in the GPA calculator are the common convention, and the table is editable precisely because your registrar's version may differ. We do not claim any named school's, district's or state's policy anywhere on this site, because we have not verified any of them and a confident wrong claim about a real institution would be worse than no claim at all.
How the numbers are checked
Every calculation lives in a small set of plain TypeScript modules with no framework attached, and every published table is generated from those same modules, never typed into the page by hand. A test suite asserts each cell of each table against arithmetic worked out independently, checks the letter boundaries of all three scales at their exact edges, and covers the awkward cases — a required exam score above 100%, a negative requirement, weights that do not sum to 100, GPA with mixed credit hours, and the floating-point rounding trap described above. It also asserts the specific numbers quoted in the prose, so an article and a table cannot drift apart.
What these tools cannot know
- Whether your instructor curves, drops the lowest score, allows a retake, or lets a final exam replace a lower test.
- Whether your school rounds a percentage before turning it into a letter, and at which decimal place.
- Whether a course counts toward your GPA at all — withdrawals, pass/fail and transfer credits are handled differently everywhere.
- Whether an assignment is excused (leave it out) or a genuine zero (put it in). Only you know which.
- Anything your portal knows and you have not typed in, including extra credit and late-posted scores.
Treat any result here as a well-checked arithmetic answer to the question you asked, not as your grade. Your grade is what your instructor records, and the document that predicts it is your syllabus.
Privacy, in one paragraph
Your scores are processed by JavaScript in your browser and are never transmitted to us. Rows are saved in your browser's local storage so they survive a reload, and the Reset button clears them. The shareable link encodes your rows into the URL itself — which means anyone holding that link can read them, so treat a shared link as public. The full privacy policy covers third-party advertising cookies and analytics.
Corrections
If a number on this site is wrong, that is a bug and it is the kind we most want to hear about. Email the specifics — the page, the inputs, the figure you got and the figure you expected — through the contact page. Reports of an incorrect calculation go to the front of the queue, ahead of feature requests.