I work for an institution whose final exam is a TOEFL ITP. My students always ask me what my judgment is about whether they will get a high score on TOEFL ITP test. They even throw some numbers, counts of correct items, randomly and ask if those numbers would be enough for them to get a target score. Well, let me state without messing: nobody can know. Not even ETS. But we can predict very accurately. And if you are just interested in your score prediction, use our calculator tool below. It will give you an estimate.
But why is it not possible to calculate my exact score beforehand even if I know the number of correct items?
TOEFL ITP is a unique exam in that it is developed by Educational Testing Service (ETS) but applied by institutions. It ensures a standardized construct of the test. However, ensuring a standard test environment is highly dependent on the institution itself. ETS, of course, has regulations and standards for this too. But even a minor change in the testing environment of a paper based test such as the height of the desks, the width of the testing room, or the location of the building etc. might effect the test results. Those effects might be positive or negative and very difficult to detect. That's why TOEFL ITP scores are not calculated with predetermined weightings. For example, we cannot say one correct listening answer is 1.2 points of your total score.
Instead of using standard weights, ETS scores each test session separately. In other words, whenever a test session occurs in an institution, it is considered to be a unique test by itself. Even if the same items and booklets were used during another session, their scoring would be different from each other. So, the group of individuals taking the test in a session has an immense effect on how the scores are calculated.
How are the scores calculated?
To answer this question, I have to talk technically a little. No worries, I will be shallow as much as I can: Statistically and hypothetically speaking, if a group of individuals is crowded enough to represent the population it belongs to, both the group's and population's score distribution would look the same. We call this the normal distribution, believed to be brought up by Carl Frederich Gauss. That's why it is also called the Gaussian Distribution.
What does this have to do with TOEFL ITP? Well, the Gaussian Distribution gives us an advantage. We can scale the scores of a group on the same level of the population. Actually, there are even standardized scales for that such as the z-scores and t-scores. So, basically if separate groups in different sessions are normally distributed, we can statistically place all these groups on the same scale and get comparable scores. In TOEFL ITP, that's how they manage to obtain standard scores from different test sessions. They just check if the raw scores of the group in the session is normally distributed. If so, the scores are simply converted to t-scores. Then, to make it more comprehensible, they just multiply the standardized scores of individuals with 10. That's how your TOEFL ITP score is calculated. And if the group is not normally distributed, which is a very rare case if there are enough number of students, then there are some other standardization techniques that can be utilized.
Why am I telling you all about this? Actually, my motive is to convince you that in TOEFL ITP we cannot calculate your exact scores prior to taking the test with the group in the session. We can just use conversion tables and make strong guesses. This tool is also doing the same. So, the scores here are not exactly accurate, but they are highly plausible predictions.