How does LIX measure the readability of a text?

LIX is a readability measure developed by the Swedish researcher Carl-Hugo Björnsson. It indicates how easy or difficult a text is to read. The calculation is based on two factors: the number of long words (7 letters or more) and the length of sentences (number of words between each full stop). It is important to emphasise that LIX do not take into account whether texts are convoluted or contain difficult terms. Nor does it deal with factors such as the student’s prior understanding, motivation and any visual support in the text, which all have an impact on the difficulty of a text. Therefore, the LIX score should only be seen as an approximate guide to the difficulty level of a text.

LIX scores in FrontRead

FrontRead contains different text packages with varying levels of difficulty. As a teacher, you can choose to give students different text packages so that each student can practise with texts that suit their level of reading. When training in FrontRead, students spend a lot of mental energy on familiarising themselves with the new strategies designed to increase reading speed and comprehension. Because of this, we have chosen to recommend a slightly lower LIX score for the training than what can normally be expected for the given grade level.

In FrontRead’s text packages, the LIX scores are as follows:

  • 3rd grade – LIX 10-12
  • 4th grade – LIX 15-17
  • 5th grade – LIX 15-20
  • 6th grade – LIX 20-25
  • 7th grade – LIX 25-27
  • 8th grade – LIX 20-30
  • 9th grade – LIX 30-32
  • 10th grade – LIX 32-35

LIX numbers and text packages

When choosing a text package for the students in your class, it’s important to choose a level of difficulty that matches the current level of each student and not select a text package based solely on the student’s grade level. You can use the LIX score as an indication of what level of text package each student should be training at. It is important to assign students the right text package, as a text package that is too difficult will inhibit the student’s motivation to work on their reading speed. Similarly, a text package that is too easy will not challenge the student to improve and thus the training will not have the intended effect. In the Teacher’s Guide, you can read more about LIX scores and text packages.

On this site, you can calculate LIX scores yourself.

Happy reading!