What this site is
Fifteen calculators that do arithmetic on grades you already have. Course grades, what you need on a final, GPA on the scale your school uses, and a few tools for the person doing the marking. Nothing else — no homework answers, no essay tools, no predictions about where you will get in.
It is static HTML. There is no app to load, no account to make and no spinner: the answer is in the page before any script runs, and the script only takes over when you change a number. That is a deliberate design choice, not a limitation.
Who publishes this
GradeCalc is the site. Prioton is the business behind it — a small independent publisher that builds calculator sites and does nothing else. The two names are not interchangeable and it is worth being clear about which is which: you are reading GradeCalc, and the people accountable for it trade as Prioton.
No school, district, exam board or university is involved, and nothing here is endorsed by one. Nobody pays us to describe a grading scale a particular way; the only money on these pages is display advertising, and what that means is set out below and in the privacy policy.
The practical consequence of being small is that a correction goes straight to the person who wrote the formula. That address is hello@thegradecalc.com, and the contact page explains what makes a report easy to act on.
Where the formulas come from
Every page shows the formula it uses and works an example through it, so you can check the arithmetic rather than trust it. The three that do most of the work:
- Weighted average. Each category's percentage multiplied by its weight, divided by the weights that were actually entered. Weights are normalised to their own sum, which is why a part-graded course reports your grade across what has been graded instead of scoring the rest as zero.
- Required final score.
(target − current × (1 − w)) ÷ w, withwthe final's weight as a decimal. The same expression gives your ceiling and your floor by putting 100 and 0 in place of the unknown. - GPA. Grade points multiplied by credits, summed, divided by credits. Weighted GPA adds a course-difficulty bump to each course before the same sum: 0.5 for honours and dual enrolment, 1.0 for AP and IB, capped at 5.0.
The grading scale used
US scales only. The letter bands are the common ones: A+ 97–100, A 93–96, A− 90–92, B+ 87–89, B 83–86, B− 80–82, and so on down to D− at 60–62. Grade points are 4.0 for an A, 3.7 for an A−, 3.3 for a B+, and the 4.3 scale differs only in giving an A+ 4.3 points. The full tables, and the reasons the three common scales disagree with each other, are on the letter grade to GPA page.
We do not convert international qualifications or foreign transcripts. Getting that wrong has real consequences for someone's application, and it is properly the job of a credential evaluation service.
Where a calculator stops being reliable
This is the part most calculator sites leave out, and it is the part that decides whether the number you just got is any use.
- Rounding at the boundary. Some instructors take 89.5% to an A−. Some do not. Almost none write it down. Within a point of a line, the number is not the answer — asking is.
- Replacement finals. If your final replaces your lowest test rather than sitting alongside it, your current grade changes when the final is entered, and the final-grade calculator will read low.
- Dropped scores. A syllabus that drops your lowest quiz is a different model from the one on these pages.
- Local GPA rules. Repeat policies, whether a repeated course replaces the original or averages with it, which courses are excluded from the GPA entirely — all set by your institution and none of it visible to us.
- Ungraded work counted as zero. If your gradebook shows a blank final exam as a zero, the grade it displays is not your standing. Most systems have a setting for this.
Your transcript and your syllabus are the authority. These pages are arithmetic done carefully and shown openly, which is a genuinely useful thing and not the same thing as a ruling.
How we check the numbers
Every calculator's arithmetic lives in one file, and a test suite asserts known-good values against it — including the awkward cases: a final worth 0%, a required score above 100%, a zero-credit course, a pass/fail grade, a class of one, a curve that would push a score past 100. The build also checks that the answer printed into the page matches what the calculator in your browser will produce, so the two can never quietly disagree.
If you find a number you believe is wrong, tell us what you entered and what you expected. That is a bug and we would like to know.
How this site is paid for
Display advertising, and nothing else. There is no signup, no paid tier, no email list and no affiliate link on any page. What we collect and what we do not is set out in the privacy policy.
Contact
Corrections, bug reports and questions all go to the same place: the contact page. A wrong answer is the report we most want to receive, and it is read before anything else.