Quiz Score Percentage Calculator (Formula + Examples)

TL;DR. Quiz percentage = (points earned / points possible) × 100. This page gives the formula, worked examples for the common variations (weighted, extra credit, dropping low scores), and pointers to SimpleQuizMaker’s built-in auto-scoring.

The basic formula

Quiz percentage = (Points earned ÷ Points possible) × 100

Examples:

Letter grade conversion (US standard)

| Percentage | Letter |

|---|---|

| 90–100% | A |

| 80–89% | B |

| 70–79% | C |

| 60–69% | D |

| Below 60% | F |

With +/− modifiers:

Per-question weighting

If your questions are worth different points (e.g., 5 questions × 2 pts + 5 questions × 4 pts):

Total possible = (5 × 2) + (5 × 4) = 30

If a student got 4 of the 2-point questions and 3 of the 4-point questions:

Weighted average across multiple quizzes

If 4 quizzes have different weights:

Weighted avg = (Q1 × W1 + Q2 × W2 + Q3 × W3 + Q4 × W4) ÷ (W1 + W2 + W3 + W4)

Example: 80% (W=1), 85% (W=1), 90% (W=2), 75% (W=1):

= (80 + 85 + 180 + 75) ÷ 5 = 420 ÷ 5 = 84%

Dropping the lowest score

A common student-friendly policy:

Example: scores 60, 70, 80, 90, 100. Mean = 80. Without the 60: mean = 85. Final = 85%.

Extra credit

Most common approach: add to numerator only, cap at 100%.

Example: earned 17 + 2 extra credit = 19, possible stays at 20. Percentage = 95%.

Alternative (less generous): add to both. Earned 19, possible 22. Percentage = 86%.

Curving a quiz

If a quiz turned out too hard, add a constant to every score.

Example: highest score in class is 78. Add 22 to everyone — the top becomes 100, everyone else scales up.

Excel formula

```

Percentage cell: =ROUND(POINTS_EARNED / POINTS_POSSIBLE * 100, 2)

Letter cell: =IF(P>=90,"A",IF(P>=80,"B",IF(P>=70,"C",IF(P>=60,"D","F"))))

```

For weighted average:

```

=SUMPRODUCT(scores, weights) / SUM(weights)

```

Auto-scoring in SimpleQuizMaker

SimpleQuizMaker computes percentage and letter grade automatically. Configure your school’s grading scale and weighting in settings; the dashboard shows scores per student per quiz, plus class averages and per-question item statistics.

You never have to open a spreadsheet for quiz grading again.

Related reading

Common conversions: raw score to letter grade

A 10-question quiz where each item is worth one point:

| Raw score | Percentage | Typical letter (US) |

|---|---|---|

| 10 | 100% | A |

| 9 | 90% | A- |

| 8 | 80% | B |

| 7 | 70% | C |

| 6 | 60% | D |

| 5 or below | <60% | F |

A 25-question quiz (the most common format for unit tests):

Weighted quizzes — when not every question is worth the same

In many classes, harder items carry more weight. A quiz with two 1-point recall items and three 3-point application items has 11 possible points, not 5. The percentage calculation:

(weighted points earned ÷ 11) × 100

A student getting both recall items right (2 points) and two application items right (6 points) scores 8/11 = 72.7%.

Bonus points and curving

When percentages mislead

A 60% on a vocabulary quiz and a 60% on a calculus quiz aren't equivalent in difficulty. The percentage system pretends they are. For high-stakes interpretation:

Quick mental-math conversions

For odd quiz lengths, the fast approach is: missed ÷ total = error rate. 100 minus that rate = percentage. A 7-question quiz where someone misses 2 = 2/7 = 28.6% error rate = 71.4% score.

Auto-grade your next quiz →

Setting a defensible passing threshold

Most of this page assumes the grading scale is fixed. In practice, you often get to choose the cutoff — and the choice should follow from what the quiz is for.

A useful sanity check: compute what the threshold means in raw questions. A 70% cutoff on a 10-question quiz means 7 right — one careless slip separates pass from fail. On short quizzes, consider either more questions or a more forgiving cutoff, because each item swings the percentage by 10 points or more.

Decide your rounding policy before you grade

Rounding disputes are the most common grade appeal, and they are entirely avoidable. Pick one rule and state it in the syllabus:

Whichever you choose, apply it identically to every student. Consistency matters more than generosity.

Handling partial credit cleanly

Percentage math gets messy when items are not simply right or wrong. Two approaches that keep the arithmetic honest:

Avoid mixing schemes within one quiz. If some items give partial credit and others do not, students will (reasonably) ask why.

Skip the by-hand math when you can

Everything above is worth understanding, but for day-to-day grading you should not be doing it manually. The free quiz grade calculator handles raw-score-to-percentage-to-letter conversion instantly, including custom scales. And if the quiz itself lives in SimpleQuizMaker, scores, percentages, class averages, and per-question statistics are computed the moment a student submits — the free plan covers up to 100 student submissions per month, which is enough for most single-class use. Teachers running multiple sections can compare options on the pricing page.

Frequently Asked Questions

How do I calculate a quiz score as a percentage?

Divide the points earned by the total points possible, then multiply by 100. For example, 17 correct out of 20 questions is 17 divided by 20, times 100, which equals 85%. If questions carry different point values, sum the earned points and divide by the total possible points rather than counting questions.

What is 7 out of 10 as a percentage and letter grade?

7 out of 10 is 70%, which is typically a C on the standard US grading scale (or a C- if your school uses plus/minus modifiers, where C- covers 70–72%). The same math applies at any scale: 14 out of 20 and 21 out of 30 are also 70%.

Should I round quiz percentages up?

Pick one rounding rule, write it in your syllabus, and apply it to everyone. The cleanest approach is to keep individual quiz scores unrounded in your gradebook and round only the final course grade, using standard round-half-up. Rounding each quiz before averaging compounds small errors and can inflate term grades noticeably.

Is there a free tool that calculates quiz grades automatically?

Yes. SimpleQuizMaker offers a free quiz grade calculator that converts raw scores to percentages and letter grades with custom grading scales. If you create the quiz in SimpleQuizMaker itself, grading is fully automatic — each submission is scored instantly, and the free plan supports up to 100 student submissions per month and 5 AI quiz generations per month.