Lexile® Measures and Grade Levels
MetaMetrics has studied the ranges of Lexile reader measures and Lexile text measures at specific grades in U.S. schools to help describe the typical Lexile ranges of texts and students of a given grade level. There is no direct correspondence between a specific Lexile measure and a specific U.S. grade level. Within any grade, and in any setting, there will be ranges of readers and ranges of reading materials. There will always be some readers who are ahead of the typical reader for the specific setting and some who are behind. For example, to say that some books are “just right” for a sixth grader or a ten-year-old in the U.S. assumes that all sixth graders or all ten-year-olds read at the same level. Furthermore, for non-native readers of English, the range of reading abilities in a given grade or age may vary significantly when compared to readers in U.S. schools. These differences can be due to the amount of prior experience with English, the reading curriculum, and other factors related to the student’s level of reading ability in his or her native language. Thus, the reading abilities of sixth graders in Korea or Brazil may not directly compare to native language readers of English who share the same approximate grade level.
This information is for descriptive purposes only and should not be interpreted as a prescribed guide about what an appropriate reader measure or text measure should be for a given grade.
Typical Reader Measures by Grade Level (U.S. Schools)
The table below shows the middle 50% of reader measures for each U.S. grade. The lower number in each range marks the 25th percentile of readers and the higher number in each range marks the 75th percentile of readers. It is important to note that 25% of U.S. students in the studies had measures below the lower number and 25% had measures above the higher number. Data for the reader measures came from a national sample of U.S. students reading in English.
|Grade||Reader Measures, Mid-Year
25th percentile to 75th percentile (IQR)
|1||Up to 300L|
|2||140L to 500L|
|3||330L to 700L|
|4||445L to 810L|
|5||565L to 910L|
|6||665L to 1000L|
|7||735L to 1065L|
|8||805L to 1100L|
|9||855L to 1165L|
|10||905L to 1195L|
|11 and 12||940L to 1210L|
The Lexile measure for a reader can be higher or lower than the measures indicated in the preceding table. If the measure is higher, this means that the reader can be expected to read age-appropriate materials very well. If the measure is lower, the reader can be expected to have difficulty reading age-appropriate materials and may require additional support.
Typical Reading Demands by Grade Level (U.S. Schools)
In 2009, MetaMetrics conducted a research study designed to examine collections of textbooks in English designated for specific grades in the U.S. education system. The Lexile ranges provided in the table and graph below describe the middle 50% of Lexile measures observed in the study, or the range of reading demands between the 25th and 75th percentile. It is most important to note the gradual increase of reading demands across all U.S. grades, rather than the relatively minor differences that may exist between grades. Such differences can be due to a variety of factors, such as differences in subjects typically taught in each grade.
Notice that there is considerable overlap between the U.S. grades. This is typical of student reading abilities and the reading demands of texts published for each grade in the U.S. In addition, the level of support provided during reading and reader motivation may have an impact on the reading experience. Students who are interested in reading about a specific topic (and are therefore motivated) often are able to read text at a higher level than would be expected based on the reader’s Lexile measure.
Although a student may be an excellent reader in English, it is incorrect to assume that he or she will comprehend text typically found at (and intended for) a higher U.S. grade level. A high Lexile measure for a student in one grade indicates that the student can read age appropriate materials at a very high comprehension rate. The student may not have the background knowledge or maturity to understand material written for an older audience. It is always a good idea to preview materials for appropriateness based on the student’s age and maturity prior to selecting materials for the student.
It is important to note that the Lexile measure of a book refers to its text difficulty in English only. A Lexile measure does not address the content or quality of the book. Lexile measures are based on two well-established predictors of how difficult a text is to comprehend: word frequency and sentence length. 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 measure is a good starting point in the book-selection process, but these other factors should be considered as well.
The real power of Lexile measures is in matching readers to text—no matter where the reader is in the development of his or her English reading skills. Matching readers with texts at the right level can help increase learning and improvement.