A Lexile measure cannot be derived from the text itself
Lexile is a measure owned by MetaMetrics, and the regression that turns a passage into a number is not published. Word frequency and sentence length are known to be involved, but there is no way to reproduce the same value independently. This page therefore never generates a measure from pasted text. Enter the measure printed with the book or passage and the measure from your own test report, and it interprets the relationship between those two numbers.
How it is interpreted
The target range is built from your own measure using the widths you enter below and above it. Different programs suggest different widths, so nothing is fixed here, and the range actually applied is printed with the result. Both ends of the range count as inside it. Grade bands also vary by source, so the low and high ends are inputs, and the page shows separately where your measure and the text sit in that band.
Limits
Two texts with the same measure read very differently when you already know the subject. The grade band is an approximation from whatever source you used, not a figure this page supplies.
Frequently Asked Questions
No. Lexile is a proprietary MetaMetrics measure and the formula is not published, so producing a number from a passage would be inventing one. Enter the measure printed with the book or passage instead.
How far below and above a reader measure still counts as suitable differs by program and by source. Fixing one value would give a wrong verdict to anyone using a different guideline, so the widths are inputs and the applied range is shown with the result.
Enter it as a negative number. A measure printed as BR200L goes in as -200, which keeps the range arithmetic correct.