The Inflesz index is a metric designed to evaluate the readability of texts in Spanish. It is based on the formula Flesch-Szigriszt, an adaptation of the well-known Flesch Reading Ease, adjusted to the linguistic particularities of Spanish.
Its main objective is to measure how easy or difficult it is to understand a text for an average reader. This index assigns a numerical value ranging from 0 to 100: the higher the value, the easier it is to read the text.
How is the Inflesz index calculated?
The Inflesz calculation is based on the following legibility formula in Spanish:
- Inflesz = 206.835 – (62.3 × P) – (1.015 × F)
Where:
- P is the average number of syllables per word.
- F is the average number of words per sentence.
Both metrics are extracted from the morphosyntactic analysis of the text. In practical terms, a text with short sentences and simple words will tend to have a higher Inflesz, while texts with long sentences and technical or dense vocabulary will reflect a lower index.
What is the Inflesz index for?
This index is very useful for various purposes:
- Education: Evaluate the adequacy of school textbooks according to the student’s level.
- Marketing: Write accessible texts for mass audiences.
- Journalism: Guarantee information clarity.
- Legal or medical field: Adapt complex documents to clearer language.
- Institutional communication: Adjust newsletters, reports and messages to the reading level of the target audience.
In summary, Inflesz helps improve written communication, making it more understandable and effective.
How to interpret the values of the Inflesz index?
Here is a general guide to understand the values of Inflesz:
For example, an Inflesz of 60 indicates “normal” readability, suitable for an average adult reader.
| Inflesz Value | Level of readability | Suggested audience |
|---|---|---|
| 80–100 | Very easy | General public, children |
| 65–79 | Pretty easy | Average teenager |
| 55–64 | Normal | Standard Adult Reader |
| 40–54 | Something difficult | Specialized audience |
| 0–39 | Very difficult | Expert readers |
What is a good Inflesz value?
It depends on the context. For texts aimed at the general public (such as blogs or information brochures), an Inflesz higher than 65 is recommended. For technical or scientific texts, a value between 40 and 55 may be acceptable, as long as the audience is familiar with the topic.
What is the difference between Inflesz and other readability indices?
Although there are several indexes (such as Flesch Reading Ease in English or Fernández-Huerta also in Spanish), Inflesz is one of the most adapted to modern texts in Spanish. Its main advantage is its precision in grammatical structures typical of the Spanish language, such as the use of subordinate clauses and common multisyllabic words.
Conclusion
The Inflesz index is an essential tool to improve the quality and effectiveness of texts written in Spanish. Knowing how to calculate it, interpret it and adapt it to the communicative context can make a big difference in how your message is received.
Do you write for others? Do you write technical content? Then the Inflesz should be part of your toolbox.
