How to Calculate Your Grade
Study guide · Updated July 2026
Turning a raw score into a grade is easy; the parts students get wrong are combining several pieces of work into one figure and working out what they still need on a final to hit a target. This guide walks through all of it — a single test, letter and classification bands, weighted grades, the reverse "what do I need" calculation, and the rounding rule that quietly decides borderline results. If you just want the number for one test, the grade calculator gives the percentage and letter instantly; read on to handle everything around it.
Turning a score into a percentage
A single test grade is your score divided by the total marks available, multiplied by 100.
Examples.
- 38 out of 45: (38 ÷ 45) × 100 = 84.4%
- 14 out of 30: (14 ÷ 30) × 100 = 46.7%
- 8 out of 15: (8 ÷ 15) × 100 = 53.3%
"X out of Y" is really just one number as a percentage of another — the exact job the "X is what percent of Y" calculator does — so any score-to-percentage question is the same piece of arithmetic dressed up in classroom language.
Letter grades and classification bands
A percentage only becomes a "grade" once it lands in a band. The bands differ by country and institution, but the two most common are the US letter scale and UK degree classifications:
| Percentage | US letter | UK degree class |
|---|---|---|
| 90–100% | A | — |
| 70–89% | B / C | First (70+) |
| 60–69% | D | 2:1 (upper second) |
| 50–59% | F | 2:2 (lower second) |
| 40–49% | F | Third / pass |
The gap is striking: 65% is a mediocre D in a US high school but a strong 2:1 at a UK university. The same number means very different things, so always read your own grading scale rather than a generic one.
Weighted grades: combining several pieces of work
Most courses are not a single test. Coursework, quizzes, and a final each carry a different weight, and your overall grade is the weighted average — not a plain average. Multiply each part's percentage by its weight (as a decimal) and add them up.
Example. Coursework is worth 40% and you scored 72%; the final is worth 60% and you scored 65%.
A plain average of 72 and 65 would give 68.5% — close here, but the more lopsided the weights, the further a plain average drifts from the truth. When there are several components, the weighted average calculator takes each grade and its weight and returns the overall figure without the manual multiplication.
What do I need on the final?
This is the question worth its weight in gold before exam week. Take your target overall grade, subtract the marks you have already banked (each weighted), then divide by the weight of the part still to come.
Example. You want 80% overall. You have 74% across work worth 70% of the course, and the final is worth the remaining 30%.
- Banked: 0.70 × 74 = 51.8
- Still needed: 80 − 51.8 = 28.2
- On the final: 28.2 ÷ 0.30 = 94%
The reality check built into this maths: if the answer comes out above 100%, the target is out of reach and you should aim for the next band down. If it comes out negative, you have already secured the grade whatever happens on the final.
Dropped scores, extra credit, and resits
Real syllabuses add wrinkles. If your lowest quiz is dropped, remove both its score and its marks from the totals before dividing — do not just delete the percentage. Extra credit is added to the marks you earned but usually not to the total possible, which is why a few bonus points can lift a grade more than they seem to. And a capped resit (say, marked out of a maximum of 40%) means the resit percentage is applied to that cap, not to the full paper. Always fold these rules into the raw marks first, then convert to a percentage.
The rounding trap
89.5% is not automatically an A.Whether it rounds up depends on your institution's policy. Some round to the nearest whole percent; many keep the raw figure, so 89.5% stays a B. On a borderline result, a fraction of a percent can decide the letter — check the exact rule rather than assuming the rounding goes your way.
Percentage grade vs. GPA
A percentage and a GPA answer different questions. A percentage is one score out of 100 on a single test or course. A GPA takes the letter grades from many courses, converts each to points on a scale (typically 4.0), and averages them weighted by credit hours — so a four-credit course moves your GPA four times as much as a one-credit one. Get the letter grade from each course first, then the GPA calculator combines them into a single cumulative number.
Do it instantly
Once the method is clear, you rarely need to do it by hand. The grade calculator turns a score into a percentage and letter; the weighted average calculator handles courses with mixed weights. And if the underlying percentage steps still feel shaky, the guide on how to calculate percentages covers the three problems every grade calculation is built from.
Frequently asked questions
What grade is 38 out of 45?
38 ÷ 45 × 100 = 84.44%, which is a B on the standard US scale (an A usually starts at 90%). The method is the same for any test: divide your score by the total marks and multiply by 100.
How do I combine coursework and an exam into one grade?
Multiply each part's percentage by its weight, then add them. If coursework is worth 40% and you scored 72%, and the exam is worth 60% and you scored 65%, your overall grade is (0.40 × 72) + (0.60 × 65) = 28.8 + 39 = 67.8%.
What score do I need on the final to get the grade I want?
Subtract the weighted marks you already have from your target, then divide by the final's weight. Wanting 80% overall, with 74% banked across work worth 70% of the course and a final worth 30%: (80 − 0.70 × 74) ÷ 0.30 = 28.2 ÷ 0.30 = 94% needed on the final.
Does 89.5% round up to an A?
It depends entirely on your institution's rule. Some round to the nearest whole percent (so 89.5 becomes 90, an A); many do not round at all, leaving 89.5% as a B. Never assume — check the syllabus, because a fraction of a percent can cross a grade boundary.
Is a percentage grade the same as a GPA?
No. A percentage measures marks on one test or course out of 100. A GPA converts letter grades to points (usually on a 4.0 scale) and averages them across courses weighted by credit hours. You need the letter grade first, then the GPA calculator turns several of them into one number.