Why this exists
Most grade calculators answer half the question. They return a required score and stop, which leaves the actual question unanswered — how badly can I do and still be fine? That is what a student scrolling on a phone at eleven at night is really asking, and it is why every calculator here shows the full range of outcomes alongside the single threshold: what a perfect exam gets you, what a zero leaves you with, and where each score in between lands.
The other half of the problem is trust. A number is only useful if it is right, so the arithmetic is written as pure functions, isolated from the interface, and covered by a unit test suite that includes every edge case the tool can hit: a final worth 0% of the grade, a final worth 100%, required scores above 100, required scores below zero, grades above 100 from extra credit, and category weights that do not add up.
How the math is verified
Every calculation lives in one file with no interface code in it, and every function in that file has tests. Three rules are enforced by those tests:
- Required scores round up, never down. If you need 87.42%, the site says 87.42% — never 87.4%. Rounding down would tell a student they are safe at a score that leaves them short.
- No calculation ever divides by zero. A final worth 0% of your grade, a final worth 0 points, and categories weighted at 0% all return a plain-language explanation instead of a broken number.
- Nothing is silently normalised. If your categories total 60%, you are told that, and the result is labelled as your grade on completed work. Scaling those categories up to 100% behind your back would turn a partial grade into something that looks final.
What this site does with your data
Nothing. There is no account, no database, and no server that receives what you type. Every calculation runs in your browser as JavaScript on the page you are already looking at. Close the tab and the numbers are gone. The privacy policy covers the one exception — third-party advertising cookies — in detail.
How it pays for itself
Display advertising, and nothing else. There is no premium tier, no email capture, no newsletter gate, and nothing is sold. Ads are placed below the result and inside the article — never next to an input or a button, because an ad positioned to catch a mis-tap is bad for you and gets ad accounts terminated. Every ad slot reserves its space in the layout before it loads, so nothing on the page jumps while you are reading.
Accuracy, and its limits
The arithmetic is correct. Whether it applies to your class is a separate question, and there are three common reasons it might not:
- Minimum final exam scores. Some courses require a specific score on the final to pass at all, regardless of your course average. That rule overrides any calculation.
- Dropped or replaced scores. Drop-lowest policies and finals that replace a lower midterm change the inputs, and no general calculator can guess them.
- Rounding policies. An 89.5% is an A- at some schools, a B+ at others, and truncated at a third.
All three are in your syllabus. Read it before you make a decision based on a number from any calculator, including this one.
Corrections
If a number here looks wrong, that is worth knowing about. Send the inputs you used and the result you expected to cannon.potter1@gmail.com — a reproducible case is fixed quickly. More detail on what to include is on the contact page.