College GPA & grade conversion explained

Last updated: 2026-06-25

Credits vs. grade points: what's the difference

In college, "credits" can mean two things. One is the credit hours that represent a course's weight. A 3-credit course usually meets three hours a week and a 1-credit course one hour. When you hear that you need a certain number of credits to graduate, that's this kind. The other is the grade points that turn a letter grade into a number — treating an A+ as 4.5 or a B as 3.0.

Combining these two gives your GPA, the Grade Point Average. GPA is not a simple arithmetic mean of your grades; it is a weighted average that uses each course's credit hours as the weight. So a grade in a high-credit core major course affects your average far more than a 1-credit elective.

The GPA formula

Your GPA is calculated as follows.

GPA = Σ(course grade points × course credits) ÷ Σ(course credits)

The numerator is the sum of each course's grade points times its credits, and the denominator is the sum of credits for graded courses. For example, suppose you took these three courses in a term.

Here the GPA is 32.0 ÷ 8 = 4.0. A simple arithmetic mean would give (4.5 + 3.5 + 4.0) ÷ 3 ≈ 4.0, which is close — but once courses with very different credits are mixed, the two values diverge sharply. For an exact figure, enter your courses into the GPA calculator and get the result at once.

Grade scales: 4.5 / 4.3 / 4.0

The same grade yields a different number depending on the maximum scale a school uses. The most common at Korean universities is the 4.5 scale, where A+ is 4.5. Some schools use a 4.3 scale (A+ = 4.3), and others use a 4.0 scale where A and A+ are both 4.0.

Grade and percentage conversion

For scholarships, grad-school applications and overseas submissions you may need to convert your GPA to a different scale or a percentage. The simplest and most widely used method is the ratio conversion.

• Scale → scale: converted GPA = your GPA ÷ your max × target max
• GPA → percentage: percentage = GPA ÷ max × 100

For example, 4.1 on a 4.5 scale becomes 4.1 ÷ 4.5 × 4.3 ≈ 3.92 on the 4.3 scale, and 4.1 ÷ 4.5 × 100 ≈ 91.1% as a percentage. You can do this directly in the grade scale converter. To turn a percentage score into a letter grade instead, use percentage to grade. Remember that a ratio conversion is only an approximation: evaluators like WES and grad schools often use their own tables, so for official submissions always confirm the method your recipient accepts.

Handling F, P/NP and retakes

To calculate GPA accurately you need to know how special grades are handled. An F (fail) enters as 0.0 grade points and is included in your credits, dragging your average down sharply. That is why a single F is hard to offset even with several A's the next term.

P/NP (Pass/Non-Pass) courses are usually excluded from the GPA. The credits count, but they don't affect your average, so some students take demanding electives Pass/Fail as a strategy. Note that graduation requirements or major requirements may limit how many P/NP courses count.

Retakes are where school rules vary the most. Some schools automatically replace with the higher grade, some cap the retake grade (for example at A), and some keep the original grade on the transcript. If you plan a retake to raise your GPA, check your school's academic policy first.

How class rank differs

High-school class rank is calculated differently from college GPA. Class rank is a relative system that assigns a band from the cumulative percentile of your rank in each subject. In the 9-tier system the top 4% is band 1, up to 11% is band 2, and so on; from the 2025 first-year cohort it shifts to a 5-tier system. To find your band from your rank and class size, use the class rank calculator.

Summary

• GPA = Σ(grade points × credits) ÷ Σ(credits) — a credit-weighted average.
• Grade scales (4.5/4.3/4.0) and percentages convert by ratio, but it's an approximation.
• An F counts as 0 and lowers your average; P/NP is excluded from the GPA.
• Retake and rounding rules differ by school, so check your academic policy.
• High-school class rank is rank-based relative grading, calculated differently from GPA.

Last updated: 2026-06-25