rubyImage: rubyNormal curve equivalent (NCE): A normalized standardized score with a mean of 50 and a standard deviation of 21 resulting in a near equal interval scale from 0 to 99. Normal curve equivalent - Wikipedia Was this helpful? Normal curve equivalent - Wikipedia the normal equivalent score is 50 if the percentile rank of the raw score is 50; the normal equivalent score is 1 if the percentile rank of the raw score is 1. This relationship between normal equivalent scores and percentile ranks does not hold at values other than 1, 50, and 99.[PDF] What is a Normal Curve Equivalent Score? The Normal Curve Equivalent, or NCE, is a way of measuring where a student falls along the normal curve. The numbers on the NCE line run from 0 to 100, similar to percentile ranks, which indicate an individual student's rank, or how many students out of a hundred had a lower score.