Test Grade Calculator

Calculate your test score and letter grade with customizable grading scale

Free, accurate, instant results - Perfect for students and teachers

Last updated: November 21, 2025

CreatorFrank Zhao

Total Questions/Points

Input Mode

Correct AnswersWrong Answers

Number of Correct Answers

Grade Scale

A+	A	A-	B+	B	B-	C+	C	C-	D+	D	D-	F
97%-100%	93%-96.99%	90%-92.99%	87%-89.99%	83%-86.99%	80%-82.99%	77%-79.99%	73%-76.99%	70%-72.99%	67%-69.99%	63%-66.99%	60%-62.99%	0%-59.99%

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Introduction / Overview

A test grade is usually just a percentage (how many points you earned out of the total) plus a letter grade based on a grading scale. This calculator automates both steps — and it supports either correct answers or wrong answers as input.

Who is it for?

Students checking scores and letter grades
Teachers building or verifying a grading scale
Parents helping kids understand how grades are computed

Why it’s reliable

The math is simple and transparent: it uses $\frac{\text{points earned}}{\text{total points}}$ and maps the percentage to your chosen grading scale. You can also edit the scale to match your school.

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Nice combo: if you’re converting fractions or decimals into percentages for homework, you may also like our Fraction to Percent Converter and Decimal to Percent Converter.

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How to Use / Quick Start Guide

Enter total questions (or total points)

This is your $T$ . Examples: $T=50$ questions, or $T=100$ points.

Choose what you know

Use Correct Answers if you know how many you got right, or Wrong Answers if you only know mistakes.

Type your number — results appear instantly

As soon as inputs are valid, you’ll see the percentage and the letter grade. Decimal values like $37.5$ work too.

Optional: customize the grading scale

Click “Edit” in Grade Scale if your school uses different cutoffs.

Core idea

\text{Score(\%)} = \frac{C}{T}\times 100

Where $C$ is correct points and $T$ is total.

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Real-World Examples / Use Cases

Example 1: You know correct answers

Background: A 50-question quiz. You got 43 correct.

\text{Score}

=

\frac{C}{T}\times 100

=

\frac{43}{50}\times 100

=

86\%

Result: $86\%$ . The letter grade depends on your scale (many schools map this to a B).

Example 2: You only know wrong answers

Background: 40 total questions. You missed 5.

C

=

T-W

=

40-5

=

35

\text{Score}

=

\frac{35}{40}\times 100

=

87.5\%

Result: $87.5\%$ — great for checking “how many wrong can I afford?” scenarios.

Scenario: Target a grade

If you want at least $90\%$ , you can back-solve the minimum correct count.

Scenario: Partial credit

Use decimals (e.g., $37.5$ points) when problems have half points.

Scenario: Compare scales

Different classes use different cutoffs. Edit the scale to see how the same percentage maps to a letter grade.

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Common Scenarios / When to Use

This calculator is especially helpful when:

You want the exact percentage from a raw score (fast, no rounding surprises).
You’re planning: “If I miss $W$ questions, what grade do I get?”
You need to match a custom grade scale (standards-based grading, honors weighting, etc.).

⚠️ Not a perfect fit: if your course uses weighted categories (homework, quizzes, exams), you’ll need a weighted average — a single test score alone won’t represent your final grade.

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Tips & Best Practices

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Use decimals when needed: if a question is worth half points, treat your score as points earned (e.g., $C=37.5$ ).

The calculator will still compute $\frac{C}{T}\times 100$ correctly.

Common mistakes to avoid

Mixing up totals (questions vs points). Use the same unit for $C$ and $T$ .
Typing $W$ (wrong) into the correct box (or vice versa).
Assuming every school uses the same letter cutoffs — always check the syllabus.

Want to see “what score do I need”?

A quick back-of-the-envelope rule: for a target percentage $p$ , you need about $C \approx \frac{p}{100}T$ correct. Round up if your teacher requires whole points.

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Calculation Method / Formula Explanation

The calculator uses two steps: compute your percentage score, then map it to a letter grade using the grading scale.

Percentage score

\text{Score(\%)} = \frac{C}{T}\times 100

If you enter wrong answers $W$ , the calculator first computes $C=T-W$ .

C

=

T-W

,

\text{Score}

=

\frac{C}{T}\times 100

Variable meanings

$T$ : total questions or total points
$C$ : correct answers or points earned
$W$ : wrong answers

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Letter grades: there’s no universal standard. Many U.S. schools use cutoffs like $90\%$ for an A, but your school may differ. That’s why the calculator lets you edit the grading scale.

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Related Concepts / Background Info

Raw score vs percentage

Raw score is just $C$ out of $T$ . Percentage normalizes it so different tests can be compared.

Rounding

Some teachers round to the nearest whole percent, others keep one decimal. If you’re right on a cutoff (say $89.95\%$ ), the rounding policy matters.

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Frequently Asked Questions

What is a “passing” grade?

It depends on the school. Many systems treat anything at or above $60\%$ as passing, but some require $70\%$ or higher.

Can I use this for points (not questions)?

Yes. Treat $T$ as total points possible and $C$ as points earned. The formula $\frac{C}{T}\times 100$ stays the same.

Why does my letter grade differ from my friend’s?

Different classes (or teachers) can use different cutoffs. Try editing the scale to match your syllabus.

How many questions can I miss and still get an A?

If an A starts at $p\%$ , then you need about $C \ge \frac{p}{100}T$ . That means wrong answers roughly satisfy $W \le T-\frac{p}{100}T$ .

Does it work for extra credit?

If extra credit adds points, include it in $C$ (points earned). If the teacher also increases the total possible, update $T$ too.

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Limitations / Disclaimers

This calculator is for educational planning and quick checks. Always follow your course syllabus or teacher’s policy for rounding, grading curves, dropped questions, and weighted categories.