The grade scale
Most GPA and class-grade calculators use the standard plus/minus 4.0 scale below, the most widely used conversion in the United States. Four tools follow an outside organization’s rules instead: the UC GPA calculator (no plus or minus, honors points capped at 8), the law school GPA calculator (LSAC’s table, A+ = 4.33, D- = 0.67), the medical school GPA calculator (AMCAS weights, D- = 0.7) and the ACT score calculator (average of three section scores). The AP score calculators are described in their own section. Its percentage bands are the same ones the College Board uses when it asks PSAT takers for their grade average (A+ 97–100, A 93–96, A- 90–92), as printed in its 2024 SAT Suite annual report. The College Board’s BigFuture conversion chart is a simpler whole-letter version (A 90–100, B 80–89, C 70–79, D 66–69, below 65 an F). Neither is universal: your school’s scale always wins.
| Letter | Minimum percent | Grade points |
|---|---|---|
| A+ | 97 | 4.0 |
| A | 93 | 4.0 |
| A- | 90 | 3.7 |
| B+ | 87 | 3.3 |
| B | 83 | 3.0 |
| B- | 80 | 2.7 |
| C+ | 77 | 2.3 |
| C | 73 | 2.0 |
| C- | 70 | 1.7 |
| D+ | 67 | 1.3 |
| D | 65 | 1.0 |
| F | below 65 | 0.0 |
Notes on this scale: an A+ is worth 4.0, the same as an A. On this scale there is no D- grade; scores below 65 are an F. Percentages are compared as entered, without rounding, so an 89.6 is a B+ here even if your teacher rounds it to a 90.
Weighted GPA
In weighted mode, Honors classes add 0.5 points and AP or IB classes add 1 point to the grade points above. A failing grade receives no bonus. These are the most common values, but districts vary; some add 1.0 for Honors or weight only certain years.
GPA
GPA is the credit-weighted average of grade points: each class’s points are multiplied by its credits, the results are added, and the total is divided by the total credits. Classes with 0 credits are ignored. Pass/fail classes and withdrawals should be left out, as most schools exclude them.
Cumulative GPA
A new cumulative GPA combines your previous GPA and the new term by their credits: (previous GPA × previous credits + term GPA × term credits) ÷ (previous credits + term credits). This assumes no class is being retaken. If your school replaces retaken grades, the real result can be higher.
Raising a GPA
The GPA needed to reach a target is (target × total credits after the term − current quality points) ÷ credits in the term. The credits of straight A’s needed is current credits × (target − current GPA) ÷ (maximum GPA − target). A target equal to the maximum can never be reached if any earlier grade was lower.
Final exam score
The score needed on a final is (goal − current grade × (1 − final weight)) ÷ final weight, with the weight written as a decimal. It assumes your current grade already reflects everything except the final, and that the final does not replace other scores.
High school GPA
The high school GPA calculator applies the same credit-weighted average year by year (9th to 12th grade) and then across all years, in both weighted and unweighted form. Percent grades are converted to letters with the scale above before they are averaged.
Semester grade
A semester grade is a weighted average of the grading periods and the semester exam: (Q1 × weight + Q2 × weight + exam × weight) ÷ total weight. If the weights you enter don’t add up to 100, they are scaled to 100. The exam score needed for a goal solves the same equation for the exam.
Grade curves
The grade curve calculator offers four standard methods: a flat add, a square-root curve (10 × √score), a linear rescale to a target mean and top score, and a bell curve that maps each score’s z-score to a target mean and standard deviation. Standard deviation is computed over the whole class (dividing by n). Bell-curve letters are relative, so they can lower some grades; the page says so.
UC GPA
The UC GPA calculator follows the University of California’s published rules: a-g courses from the summer after 9th grade through the summer after 11th, A = 4 to F = 0 with no plus or minus, and one extra point for approved honors courses, up to 8 semesters with no more than 4 from 10th grade. It reports the capped weighted, fully weighted and unweighted GPA, each linked to UC’s pages on the calculator page.
LSAC GPA
The law school GPA calculator uses the conversion table of LSAC’s Credential Assembly Service (A+ = 4.33, A = 4.00, A- = 3.67 … D- = 0.67). Every attempt that appears on a transcript counts, including repeated courses; non-punitive withdrawals and passing pass/fail grades are left out, and a failing pass/fail grade counts as 0.00. Quarter hours are multiplied by 0.67.
AMCAS GPA
The medical school GPA calculator follows the AMCAS Applicant Guide: A+ and A = 4.0 with plus and minus grades counted, every attempt included, courses classified as BCPM (biology, chemistry, physics, math) or AO (all other), and GPAs reported by academic status from freshman through graduate.
ACT Composite
The ACT score calculator averages the English, math and reading scale scores (science is optional and not part of the Composite since September 2025) and rounds the way ACT does: a fraction below one half rounds down, one half or more rounds up. The STEM score averages math and science. Raw answers are not converted to scale scores, because ACT uses a different table for each test form.
Major GPA
A major GPA is the same credit-weighted average, using only the classes you mark as counting toward your major. Which classes count is set by each school and department, so the calculator lets you choose them one by one.
Latin honors
The Latin honors calculator compares your cumulative GPA with cum laude, magna cum laude and summa cum laude thresholds: either ones you enter, or the published rules of named universities, each linked to its official page with the academic year. For schools that award honors by class percentile, it explains that your rank can’t be known from your GPA alone. The GPA needed to reach the next level uses the raise-GPA formula above.
AP exam scores
The AP score calculators turn raw section points into a weighted composite using the section weights on each course’s official College Board exam page (for example, AP Calculus AB). College Board does not publish each year’s composite-to-1–5 cut points, so the 1–5 is an estimate read from the most recent official conversion chart we could find, from released and practice exams of 2007–2013, and only for exams whose current section weights match that chart. Exams without a matching chart show the composite only. AP® is a trademark registered by the College Board, which is not affiliated with GradeDuck.
Rounding
Calculations use full precision. Results are shown with two decimals for GPAs and one decimal for percentages. Credits required are rounded up, since you cannot take part of a credit.
Which calculator uses which rule
- The grade scale and GPA formula: GPA calculator, GPA to percentage converter, EZ grader.
- Weighted GPA: weighted GPA calculator (bonuses editable for your school).
- Cumulative GPA: cumulative GPA calculator.
- Raising a GPA: raise GPA calculator.
- Final exam score and category weights: final grade calculator and grade calculator.
- Rank and percentile: class rank calculator.
- High school GPA and semester grades: high school GPA calculator and semester grade calculator.
- Grade curves: grade curve calculator.
- Organization rules: UC GPA, law school (LSAC) GPA, medical school (AMCAS) GPA and ACT score calculators.
- Major GPA and Latin honors: major GPA calculator and Latin honors calculator.
- AP exam scores: AP score calculator and AP Lang score calculator.
Testing and corrections
The formulas are covered by automated tests built from the worked examples on each page. If a result looks wrong to you, please send the numbers you used. Confirmed errors are fixed, and this page’s date is updated.