Leveling 101

By Ellen Myrick

There are several leveling systems used by schools and three of the most widespread are Lexile, Fountas & Pinnell, and ATOS. Each program has its own distinctive approach to this complicated topic. Whether you are using them solo or in tandem, we’re here to help you understand the breadth and depth of each program as well as their respective pedagogies.


Renaissance Learning is the parent company of ATOS and Accelerated Reader. Their readability formula evaluates average sentence length plus average word length plus vocabulary grade level plus the number of words in a book to arrive at the ATOS level. The ATOS level is expressed in a grade level scale. Renaissance has applied their trademarked readability formula to more than 170,000 books.


The premier product of Metametrics, the Lexile Framework for Reading has a scale that is on a continuum. They have also recently added a new range that is below BR (Beginning Reader) for those books that would fall below “0.” Twenty-four states use lexile measures on their end-of-year assessments. The lexile system is a quantitative measurement and does not take aspects of the text like age appropriateness or text quality into account. That said, they have recently added GN (Graphic Novels) though even this does not include an evaluation of the images accompanying the text. Lexile has close to 500,000 titles available and is used by the Scholastic Reading Counts program.

Fountas and Pinnell

Offered by Heinemann Publishing, F&P was introduced as Guided Reading in 1996 by Gay Fountas and Irene Pinnell. Their 26 point gradient is helpful for both small groups and whole group use. A key characteristic is that independent reading should be left for the students to choose. There are ten characteristics that contribute to a book’s F&P measure:
1. Genres and Forms
2. Text structure
3. Content
4. Themes and Ideas
5. Language and literary features
6. Sentence complexity
7. Vocabulary
8. Words
9. Illustrations
10. Book and print features.
There are just over 49,000 books with Fountas & Pinnell measurements.

At a Glance

Quantity of Titles Leveled (estimated)
ATOS 170,000
Lexile 200,000
F & P 50,000


ATOS:  Text analyzer software, based on average sentence length, word length, and word difficulty
Lexile:  Text analyzer software, based on semantic and syntactic elements of a text
F&P: Professional levelers evaluate based on ten characteristics (see above and as described in The Continuum of Literacy Learning)

Features of the Products
  ATOS Lexile F & P
Online Book Search
Online Student Reading    
Related Assessments
Educator Dashboards    
Profess. Development

Examples of Levels

ATOS 4.5. Could likely be read by a student whose reading skills are at the level of a typical 4th grader during the fifth month of school.
Lexile: 650L. If a reader has a Lexile measure of 650L, the reader will be forecasted to comprehend approximately 75% of a book with the same Lexile measure.
F&P: R. A reader with this level will be reading at a mid-4th grade instructional level.

Bound to Stay Bound includes leveling information in each book’s metadata when available to help you select the books that meet the needs of your students. On the Bound to Stay Bound site, go to “Reading Programs” on the left navigation bar to search within each program’s offerings. As you can see from the screenshot pictured here, you can also see what measurements are available for a specific title and even download a teacher’s guide if available.

For more information:


Acknowledgments: Much of the information for this article was presented at the Educational Book & Media Association Annual Meeting in January 2015. Presenters included Sue Pulvermacher-Alt from Renaissance Learning, Tim Klasson from MetaMetrics, and Lesa Scott from Heinemann Publishing. The panel was moderated by Patricia Payton of Bowker.