Knowledgebase
Converting standardised scores to Percentiles
Posted by Cynthia W on 30 December 2006 11:07 PM


The following table shows corresponding percentile scores for a range of Z scores.
Z score = Raw Score minus Mean divided by Standard Deviation To convert from any other standard score scale into a Z score, one simply subtracts the mean of the other standard scale from the standard scale score and divides by the standard deviation of the standard score scale. So, to convert a T score into a Z score: Z score = T Score minus mean of T score scale (50) divided by standard deviation of a T score scale (10). See also: What is a percentile score  
