GradeTools provides free GPA, grade, attendance and academic calculators for high school and college students.

Most grade and GPA mistakes come from the same place: treating an average as a simple one. A GPA is weighted by credit hours, a course grade is weighted by points or by category, and averaging the numbers directly gives an answer that looks plausible and is wrong.

Every calculator here shows its working — a per-course or per-assignment breakdown, so you can check the total rather than take it on trust. Where a result depends on a rule your school sets, the rule is a setting you control rather than an assumption buried in the arithmetic.

Schools differ on whether plus and minus grades carry separate values, whether an A+ is worth more than 4.0, how pass/fail and transfer credits count, what happens when a course is repeated, and what attendance is required. Two accurate GPAs for the same student can differ noticeably.

So nothing here presents one scale as official. Defaults are described as common, not standard, and every one can be changed. Where a calculation depends on institutional policy — grade replacement, weighted bonuses, attendance minimums — the page says so plainly and points you at the syllabus or registrar.

Some questions have uncomfortable answers. A target GPA can become unreachable in the credits you have left; a grade can be out of reach whatever you score on the final; an attendance requirement can run out of classes.

When that happens the calculator says so directly, shows the best outcome still available, and where it can, says what would change it — the credits it would actually take, or the score that is still in play. A number above 100% printed without comment is not an answer.