What the grade calculator does
Most courses do not average marks equally: an exam might be worth 40% of the grade, coursework 35%, and quizzes 25%. Enter each assessment with its score and its weight and the calculator returns your current weighted average — the grade you would have if the course ended today. Add hypothetical rows to see what a future score would do, or leave the final exam out to find what you need on it.
The weighted average formula
Grade = Σ (score × weight) ÷ Σ weight
Assignment Score Weight Score × weight
Homework 92 20 1,840
Midterm 78 30 2,340
Project 88 20 1,760
Final 85 30 2,550
───── ─────
100 8,490 → 8,490 ÷ 100 = 84.9%Weights do not have to add up to 100. If you enter only the assessments completed so far — say weights totalling 70 — the calculator divides by 70 and shows your average across what has been graded. Weights can also be points (an assignment out of 50, a test out of 200); the maths is identical.
What do I need on the final?
The most common question. Rearrange the formula: with current average C over completed weight W, a final worth weight F, and a target grade T:
Needed on final = (T × (W + F) − C × W) ÷ F
Current 84.9% over 70% of the course, final worth 30%, target 90%:
(90 × 100 − 84.9 × 70) ÷ 30 = (9,000 − 5,943) ÷ 30 = 101.9% → not reachable
Target 87%:
(87 × 100 − 5,943) ÷ 30 = 91.9% → reachable with a strong examA result above 100% means the target is out of reach; below 0% means it is already secured. Use the calculator by adding a “Final” row with a guessed score and adjusting until the overall grade hits your target.
Percentage to letter grade
| Percentage | US letter | UK degree class | Notes |
|---|---|---|---|
| 90–100 | A | First (70+) | UK scales are lower — a UK 70 is excellent |
| 80–89 | B | Upper second (60–69) | |
| 70–79 | C | Lower second (50–59) | |
| 60–69 | D | Third (40–49) | |
| below 60 | F | Fail (below 40) | US pass marks are usually 60–65 |
Cut-offs vary by institution and instructor; check the syllabus. Some courses curve grades to a distribution, in which case the raw weighted average is not the final grade.
Tips for using weights correctly
- Match the syllabus. If it says “Homework 20%” and there are ten homeworks, either enter one row with the homework average at weight 20, or ten rows at weight 2 each.
- Dropped lowest scores — many courses drop the lowest quiz. Leave it out.
- Points-based courses — enter the points earned as the score and the points possible as the weight, all rows in raw points, and the calculator gives the overall percentage.
- Extra credit — add it as a row with a score above 100, or add the points to the relevant assignment.
- Ungraded work — leave it out to see your current standing; add it with a guessed score to see the effect.
Grade vs GPA
This calculator works within a single course. Your GPA combines the final letter grades of many courses, each weighted by credit hours — a separate calculation handled by the GPA Calculator. Convert this course's percentage to a letter using your school's scale, then enter the letter and credits there.