International Student Admissions Test (ISAT) is a three-hour multiple mandatory test for entry into specified courses offered by some Australian educational institutions to international students.

As you asking here I am telling International Student Admissions Test (ISAT) scoring process is complex and requires substantial development and analysis by ACER's psychometricians.

Applicants cannot calculate their own scores. The ISAT scaled scores are developed as a complex interaction between candidate abilities and test item difficulties (Item Response Theory: IRT)

ISAT scores for Critical Reasoning (CR), Quantitative Reasoning (QR) and Overall are on scales with ranges of 100-200.

The use of scaled scores enables scores from the test in different years to be directly compared. (The Overall score is an average of the CR and QR scaled scores).

Percentiles

To give meaning to the scaled scores, percentile ranks are also provided.
Percentiles (%ILE) show the percentage of candidates whose scores are lower than the one reported.

Example

A student with an Overall score of 183 has a percentile rank of 81, meaning that their score is higher than that achieved by 81% of others taking the test. The candidate is thus within the top 20% of the test-taking population.