What is the Douma adaptation of Flesch?

Flesch Reading Ease was built for English with a syllable constant of 84.6. Douma recalibrated it for French in 1960, lowering that constant to 73.6 because French words carry more syllables on average. The formula otherwise keeps the 206.835 base and the 1.015 sentence-length term.

What is the exact formula used?

The score is 206.835 minus 1.015 times words-per-sentence minus 73.6 times syllables-per-word. Shorter sentences and shorter words both raise the score, meaning easier reading. The result is shown on a 0 to 100 scale.

How should I read the score band?

Roughly, 80 and above is very easy primary-school French, 60 to 79 is easy general French, 40 to 59 is fairly difficult secondary level, 20 to 39 is difficult university level, and below 20 is very difficult specialised text. Aim for 60 or higher for a broad audience.

How are syllables counted?

Syllables are counted from vowel groups, treating runs like eau and oi as one nucleus, and suppressing the silent final mute e, the plural es, and the verb ending ent. This French-aware count is what makes the Douma constant meaningful.

Why does my score differ from an English Flesch tool?

English Flesch tools use the 84.6 syllable constant and an English syllable counter, both wrong for French. They typically report French as harder than it is. Use this Douma-calibrated version for any French content.

French Flesch-Douma Readability

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This tool measures how easy a French text is to read using the Douma adaptation of the Flesch Reading Ease formula. The original Flesch index was tuned for English; applying it unchanged to French overstates difficulty, so Douma recalibrated the syllable weight specifically for French.

How it works

The score combines two ratios, sentence length and word length, into a single 0–100 number where higher means easier:

score = 206.835 − 1.015 × (words / sentences) − 73.6 × (syllables / words)

The French calibration lives in the 73.6 syllable constant, lower than the English 84.6, because French words average more syllables. Words are matched including accents and internal apostrophes and hyphens, sentences are counted from terminal punctuation (., !, ?, …), and syllables use a French-aware vowel-group count with mute-e suppression.

Tips and example

To raise a low score, do the two things the formula rewards: shorten sentences and prefer shorter, more common words. Splitting one long sentence into two lowers the words-per-sentence term directly. The tool shows both ratios so you can see which one is dragging the score down. Because the syllable count is the same engine used by the French syllable counter on this site, the readability result stays consistent with those word-level figures.