The Extensive Reading Foundation Reading Amount and Library Calculator
This tool has been made to show how many words, books and hours at given reading speeds that students need to read at each level of the ERF Graded Reader Scale. The calculations are based on covering all the headwords at a given level 20 times. (20 was chosen as most research suggests between 10-30 meetings, some of which will be intentional and some incidental). If you feel the figure is less, then downgraded the reading amounts and times, or if you feel it is higher, increase the books and hours as necessary.
IMPORTANT Note 1
These figures were calculated from a corpus of texts by a computer. So these figures only do the basic math for the amount of reading a student should do TO REACH A CERTAIN LEVEL (e.g. X book by Z time / level) in order to master the basic meaning of a word. However words often have several meanings and appear in phrases, phrasal verbs, set expressions which the computer cannot identify. So in order to master these too, the students would need to meet about double the figures given below.
IMPORTANT Note 2.
The table below is not meant to imply that this is the exact size of your library because each student will like different books so you should DOUBLE these figures at least to have a suitably sized library that covers the interests of all the students.
IMPORTANT Note 3.
Following the above Notes 1 and 2, if you want the student to meet not only the basic meanings but also the secondary meetings and see the words used in a variety of contexts to build depth of knowledge, a student need to read at least Double the amounts in the table.
In addition to the above, as each student likes different books a library should contain FOUR TIMES the number of books here. The lower part is a simple calculator for teachers to guestimate how many books they will need for X number of students at a given level. Note that even if they only have one student at a given level that student still need to read the set amount and this is reflected in the statistics. Two examples are given. You can download ERF Library Calculator as a PDF.
