How to Calculate Your Test Score Percentage (and What Grade It Is)

To find your test score as a percentage, divide the points you earned by the total points possible, then multiply by 100. If you got 42 out of 50, that’s 42 ÷ 50 = 0.84, and 0.84 × 100 = 84%. On the most common US grading scale, that’s a B.

That’s the whole formula. But tests aren’t always that tidy, so here’s how to handle the trickier cases too.

The formula

Test score % = (points earned ÷ total points) × 100

A few quick examples:

If your teacher only marked the questions you got wrong, subtract those from the total first. Missing 7 points on a 60-point test means you earned 53, and 53 ÷ 60 = 88.3%.

What letter grade is that?

Grading scales vary by school, so always check your syllabus. This is the scale most US high schools and colleges use:

Many schools add plus and minus grades, where 87–89% is a B+ and 80–82% is a B−. In the UK and Australia, marks are often reported as percentages or bands instead. At UK universities, 70% or above is usually a First.

How many questions can I miss?

This is the question everyone actually wants answered before a test. Work it out backwards.

Points you can lose = total points × (100 − target %) ÷ 100

For a 40-question test where every question is worth the same, and you want at least 90%:

• 40 × (100 − 90) ÷ 100 = 4
• You can miss 4 questions and still get exactly 90%

If you’re aiming for 80%, you can miss 8. For a 25-question quiz and a target of 90%, you can miss 2.5, so in practice 2.

When questions are worth different points

Plenty of tests mix 1-point multiple-choice questions with longer answers worth 5 or 10 points. Don’t count questions. Count points.

Say a test has:

• 20 multiple-choice questions at 2 points each (40 points)
• 3 short answers at 10 points each (30 points)
• Total: 70 points

You got 17 multiple-choice right (34 points) and scored 8, 6 and 9 on the short answers (23 points). That’s 57 out of 70, which is 81.4%.

Partial credit works the same way. Six points out of ten on a short answer counts as six, not as zero.

When the test has sections with different weights

Sometimes a test is split into parts that count for different shares of the final mark. For example, a reading section worth 60% and a writing section worth 40%.

Here you find the percentage for each section first, then weight them:

• Reading: 45 out of 50 = 90%
• Writing: 14 out of 20 = 70%
• Overall = (90 × 0.60) + (70 × 0.40) = 54 + 28 = 82%

If you’d just added the raw points (59 out of 70), you’d get 84.3%, which is wrong for this test. Weighting is also how most teachers combine tests, homework and projects into a course grade. Our guide on how to calculate your weighted grade walks through that step by step.

What about bonus points?

Extra credit is usually added to the points you earned, but not to the total. If you scored 46 out of 50 and got 3 bonus points, that’s 49 ÷ 50 = 98%. Some teachers let this go over 100%, some cap it. Check how your teacher handles it.

Common mistakes

• Dividing the wrong way round. It’s always earned ÷ total. 50 ÷ 42 gives you 119%, which is a good sign you’ve flipped it.
• Counting questions instead of points. On a mixed test, missing one 10-point question hurts a lot more than missing one 1-point question.
• Rounding too early. Keep the decimals until the end. Then round the way your school does, which is often to one decimal place.
• Assuming 89.5% is an A. Some teachers round up, many don’t. Ask before you count on it.

Skip the math

Our free Test Score Calculator gives you the percentage and letter grade the moment you enter your score. If you’re working out what you need on an upcoming exam, use the Final Grade Calculator.

Quick recap: points earned ÷ total points × 100. Count points, not questions. Weight the sections if they count differently. And always check your own school’s grading scale.

Related: the Student Study Planner & GPA Tracker keeps your grades, deadlines and timetable in one Excel file.

Related guides

• How Many Questions Can You Miss and Still Get an A?
• How to Calculate Percentage of Marks (With Examples)
• How to Calculate Percentage Increase or Decrease in Your Marks

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