Accurate Rank Calculation
Calculate accurate rank and percentile based on total students and score information. Useful for analyzing school report cards and practice test results. Enter mean and standard deviation for more accurate Z-score based rank calculation. Provides statistically reliable results assuming normal distribution of scores.
Understanding Z-Score
Z-score is calculated as (your score - mean) / standard deviation, showing how far you are from the mean in standard deviation units. Z=0 means average, positive means above average, negative means below average. Z-score allows precise percentile calculation using normal distribution tables. For example, Z=1.0 is approximately top 16%, Z=2.0 is approximately top 2.3%.
9-Level Grade System
The 9-level grade system used in Korean college entrance exams: Grade 1 (top 4%), Grade 2 (4-11%), Grade 3 (11-23%), Grade 4 (23-40%), Grade 5 (40-60%), Grade 6 (60-77%), Grade 7 (77-89%), Grade 8 (89-96%), Grade 9 (96-100%). This calculator automatically determines grade based on percentile.
Letter Grade Conversion
Internationally recognized letter grades are also provided. A+ (top 4%), A (top 11%), B+ (top 23%), B (top 40%), C+ (top 60%), C (top 77%), D (top 89%), F (remaining), allowing use with various evaluation standards.
Normal Distribution Curve Visualization
Visualize score distribution as normal distribution (bell curve) to intuitively understand your position among all students. Your score is marked on the curve, with grade boundaries displayed to see competition structure at a glance.
College Admission Data Usage
Quickly calculate grade indicators needed for college admissions or academic counseling to help with goal setting and study planning. Compare ranks from multiple tests to analyze grade trends and adjust study direction. Enter mock test results to preview expected grades for standardized tests.
