Why use grades and not reading ages?

We agree, and that is why we use Lexile as a measure rather than grades or ages. The Lexile is an objective measure of text complexity and reading comprehension. It measures both on the same scale. Therefore, it is much more accurate and specific because it identifies individual students’ level regardless of age or grade. It is more precise than ‘reading age.’ You could have two students who are the exact same ‘reading age,’ but they could be reading at extremely different levels. Because the Lexile is an objective measure, age, and grade are not factored into the results.