About the readig TOEFL scores

Hey guys!!!
I have a question about the reading section of TOEFLiBT, How can I calculate my scores? for example I get 54% of right answers from reading section, how many points I get actually? If anyone knows ,pls reply I’m absolutely frustrated.

TOEFL listening discussions: A conversation between two university students (2)

I am not so sure (as a matter of fact, i asked the same thing some days ago) but i believe you should take your percentage, divide it by 100 and then multiply the result by 30… this is the way i use!!

Thanks for the reply!!!
I found a book which calls ‘’ Pass Key to the TOEFLiBT" by Pamela Sharp, and thera was a chart of scores, for example 21 right answers in reading is scored 18. I don’t know which one is right!!! anyway thanks for the hint!!!