Comparing IELTS with other English tests
The table below shows comparisons between various test scores and level systems (like TOEIC, TOEFL and IELTS) and the VEC level system. Use this table to compare your own score or VEC level with the approximate equivalent score of another test.

Source : Cambridge English
This table shows comparison of IELTS with TOEFL and PTE (Pearson Test of English).

The main English language tests used for university entrance all report their scores on a different scale. IELTS uses a scale of 0 - 9, TOEFL IBT (Internet based test) uses numbers from 40 to 120, PTE Academic is graded from 10 to 90 and the Cambridge tests (FCE, CAE, CPE) has A - E grades.

So how do you know what your score in one test equals in one of the other tests?
This is an interesting question and there are many academics, companies and language assessment specialists who try to map the scores onto each other to produce what is called an equivalence chart. They usually look something like this:

So, how do they do it?
English language testing experts look at the content of each test and what a typical student cando at each level of each test and decide broadly what a grade or score in one test means in another.This may be different according to the content of the test for example if one test has more speakingor writing or based on statistics of previous students who took a particular test. Equivalence chartsare often reviewed by universities every few years based on the performance of previous students on university courses who were admitted with a certain test or test score.

Why is there not one standard equivalence chart?
This is mainly because the tests are not measuring the exactly the same skills in exactly the same way so an exact comparison is impossible to make. The various equivalence charts can differgreatly depending on who did the comparison. Remember that the grading systems are differentand the way of marking is different too. Some tests use computer marking only while others usehuman markers only or a combination of both.

What does this mean for students trying to enter university in an English speaking country?
Firstly it means doing some research - often the university equivalence chart is a public document so you can see what scores are being asked for each test. This way you can see if your test score meets the requirements or use the equivalence chart to help you decide which test to take. You may notice that universities have different equivalence charts which could affect the test you choose to do for specific universities or as a result of looking at equivalence charts you might change your mind about which universities to apply to.