Overview

The High School 5-Tier Grade Calculator reflects Korea's new grading system, fully implemented for first-year high school students starting in 2025 (affecting the 2028 college admissions cycle). Enter your raw score, class average, and standard deviation to obtain both your relative rank grade (5-tier) and your absolute achievement level (A–E). Unlike the previous 9-tier system, Tier 1 was expanded from the top 4% to the top 10%, easing grade competition, and report cards now list both achievement level and rank grade together.

Formula

Z-score = (Raw Score - Class Average) / Standard Deviation
Percentile Rank = (1 - Φ(Z)) × 100 (Φ = standard normal CDF)

Rank Grade (5-tier relative):
Tier 1: Top 10% / Tier 2: 10%–34% / Tier 3: 34%–66% / Tier 4: 66%–90% / Tier 5: 90%–100%

Achievement Level (A–E absolute):
A: 90+ / B: 80+ / C: 70+ / D: 60+ / E: below 60

How to Use

1. 1Enter your raw score for the subject.
2. 2Enter the class average shown on your report card.
3. 3Enter the standard deviation shown on your report card.
4. 4Enter the number of enrolled students to also estimate your class rank.
5. 5Both the relative rank grade and the absolute achievement level are shown together.

Tips

• ✔Under the 5-tier system, the Tier 1 quota grows to the top 10%, making Tier 1 easier to reach than the 9-tier system — but with lower differentiation, managing your achievement level (A–E) also matters.
• ✔Since report cards list both achievement level and rank grade, aim to secure a raw score of 90+ (A) while also managing your rank grade.
• ✔In subjects with a small standard deviation, even a small score difference can shift your grade, so minimize careless mistakes.
• ✔Common and general-elective subjects report a rank grade, but some career/convergence electives may report only the achievement level (A–E).

FAQ