A Lexile measure is a valuable piece of information about either an individual's reading ability or the difficulty of a text, like a book or magazine article. The Lexile measure is shown as a number with an "L" after it — 880L is 880 Lexile.

A student gets his or her Lexile reader measure from a reading test or program. For example, if a student receives an 880L on her end-of-grade reading test, she is an 880 Lexile reader. Higher Lexile measures represent a higher level of reading ability. A Lexile reader measure can range from below 200L for emergent readers to above 1600L for advanced readers. Readers who score below 0L receive a BR for Beginning Reader.

A book, article or piece of text gets a Lexile text measure when it's analyzed by MetaMetrics. For example, the first "Harry Potter" book measures 880L, so it's called an 880 Lexile book. A Lexile text measure is based on the semantic and syntactic elements of a text. Many other factors affect the relationship between a reader and a book, including its content, the age and interests of the reader, and the design of the actual book. The Lexile text measure is a good starting point in the book-selection process, with these other factors then being considered. Lexile text measures are rounded to the nearest 10L. Text measures reported below 0L are reported as BR for Beginning Reader.

The idea behind The Lexile Framework for Reading is simple: if we know how well a student can read and how hard a specific book is to comprehend, we can predict how well that student will likely understand the book. For example, if a reader has a Lexile measure of 600L (600 Lexile), the reader will be forecasted to comprehend approximately 75% of a book with the same Lexile measure (600L). When the Lexile measures and the Lexile scale were developed, the 75% comprehension rate was set at the point where the difference between the Lexile reader measure and the Lexile text measure is 0L. The 75% comprehension rate is called “targeted” reading. This rate is based on independent reading; if the reader receives help, the comprehension rate will increase. The target reading rate is the point at which a reader will comprehend enough to understand the text, but also will face some reading challenges. At this point, a reader is not bored by text that is too easy, but also does not experience too much difficulty in understanding.

When used together, Lexile measures help a reader find books and articles at an appropriate level of difficulty (visit Find a Book), and determine how well that reader will likely comprehend a text. You also can use Lexile measures to monitor a reader's growth in reading ability over time.

Lexile Measures Help Readers Grow, and Help Parents and Teachers Know

Teachers and parents can best serve a student's literacy needs when they treat him or her as a unique individual, rather than as a test score or a grade-level norm or average. The reading abilities of young people in the same grade at school can vary just as much as their shoe sizes. However, grade-leveling methods commonly are used to match students with books.

When a Lexile text measure matches a Lexile reader measure, this is called a "targeted" reading experience. The reader will likely encounter some level of difficulty with the text, but not enough to get frustrated. This is the best way to grow as a reader—with text that's not too hard but not too easy.

When you receive a Lexile measure, try not to focus on the exact number. Instead, consider a reading range around the number. A person's Lexile range, or reading comprehension "sweet spot," is from 100L below to 50L above his or her reported Lexile measure. Use this Lexile range in our Find a Book search. And don't be afraid to look at books above and below someone's Lexile range. Just know that a reader might find these books particularly challenging or simple.

If a student tackles reading material above his or her Lexile range, consider what additional instruction or lower-level reading resources might help. Ask him or her to keep track of unknown words, and look them up together. Or take turns reading aloud to each other to chop up the reading experience into smaller portions. Likewise, you can reward students with books that fall below his or her Lexile range for an easier reading experience.