Lexile Score: What It Is and What It Means
A Lexile measure is a number that describes the difficulty of a text or the reading ability of a reader on the same scale. Developed by MetaMetrics, Lexile measures are used by schools, libraries, and publishers to match readers to appropriately challenging books.
What Does the Number Mean?
Lexile measures are expressed as a number followed by “L” — for example, 650L or 1050L. A higher number indicates greater reading complexity. When a reader’s Lexile measure and a book’s Lexile measure are close, the reader is likely to understand the book well. When the book is 100–250L above the reader’s measure, the book is a good “stretch” text.
How Is a Reader’s Lexile Determined?
A reader receives a Lexile measure from a reading assessment, not a separate Lexile test. Tests that report Lexile measures include the STAR Reading assessment, many state standardized tests, and some MAP reports. Lexile measures are calculated from the student’s performance on reading comprehension questions involving texts of known difficulty.
Lexile Ranges by Grade Level
MetaMetrics publishes grade-level Lexile bands each year. These are approximate typical ranges:
| Grade | Typical Lexile Range (mid-year) |
|---|---|
| 1st | Up to 300L |
| 2nd | 170L–545L |
| 3rd | 415L–760L |
| 4th | 635L–950L |
| 5th | 770L–1080L |
| 6th | 855L–1165L |
| 7th | 925L–1235L |
| 8th | 985L–1295L |
| 9th–10th | 1050L–1335L |
| 11th–12th | 1080L–1355L |
For a more detailed breakdown with how to use these ranges to choose books, see Lexile Bands by Grade Level.
How to Use a Lexile Measure Practically
The most practical use for parents is book selection. If your child’s Lexile measure is 750L, look for books in the 750L–1000L range for independent reading. You can search for books by Lexile range at the Lexile Find a Book tool on MetaMetrics’ website.
Limitations of Lexile Measures
Lexile measures text complexity based on sentence length and word frequency, but they do not measure content difficulty, abstract concepts, or emotional maturity. A book with simple language about a complex topic may have a lower Lexile than a book with complex language about a simple topic. Always consider subject matter, not just Lexile, when selecting books for your child.