Coleman-Liau Index PT

The Coleman-Liau index estimates how demanding a text is from two averages: letters per hundred words and sentences per hundred words. The difference from Flesch is the ingredient — Flesch counts syllables, which need syllabification and go wrong on hiatus and diphthongs; Coleman-Liau counts letters, which any program counts with no ambiguity at all.

Paste the text and the page shows the intermediate counts and the index. The result is expressed as a US school grade: a value of 8 means the text is comprehensible to someone who finished eighth grade there. Seeing the parts separately helps explain where the number comes from — a text with long words and short sentences can score close to one with short words and long sentences, by opposite routes.

An honest caveat: the formula's constants were calibrated on English texts, and no consolidated adaptation exists for Portuguese as it does for Flesch. Portuguese words average longer, so the index tends to come out higher than the English equivalent for the same real difficulty. Use it to compare two versions of the same text, where the bias cancels, rather than as an absolute schooling grade.