How the score is calculated
- Counting. Words are letter-sequences (apostrophes and hyphens allowed);
sentences are split on
. ! ?; syllables use the standard heuristic — count vowel groups (a e i o u y), drop one for a silent trailing e, minimum one per word. Words of three letters or fewer count one syllable. These are heuristics: abbreviations and unusual words shift counts slightly. - Flesch Reading Ease.
206.835 − 1.015 × (words ÷ sentences) − 84.6 × (syllables ÷ words). Very simple text can score above 100 and dense text below 0; we display the value clamped to 0–100 and note when clamping occurred. - Flesch-Kincaid grade.
0.39 × (words ÷ sentences) + 11.8 × (syllables ÷ words) − 15.59. Negative results display as grade 0. - Passive voice — an estimate. A sentence is flagged when it matches
(am|is|are|was|were|be|been|being) + past participle(a word ending in -ed/-en, optionally after an adverb). This regex heuristic misses irregular participles like “made” and can flag adjectives like “interested” — treat the percentage as directional, not exact. It is labeled (estimate) everywhere it appears. - Legalese density. The text is scanned against a built-in lexicon of 46 terms (herein, thereof, whereas, notwithstanding, pursuant to, indemnify, force majeure, in perpetuity, null and void, witnesseth, shall… — “shall” is counted because its density is the classic drafting tell). We report the raw count and the density per 1,000 words. Lexicon as of July 2026 — directional, not exhaustive.
- The 0–100 score — exact weights. Four factors, each normalized to
0–100, combined as
score = 0.40·A + 0.20·B + 0.20·C + 0.20·D:A= Flesch Reading Ease clamped to 0–100 (40%).B= sentence length:100 × (40 − avg words/sentence) ÷ 28, clamped — full marks at ≤ 12 words, zero at ≥ 40 (20%).C= active voice:100 − 2 × passive%, clamped — zero when half the sentences read passive (20%).D= plain language:100 − 2.5 × legalese-per-1,000-words, clamped — zero at 40 lexicon hits per 1,000 words (20%).
What this doesn’t measure: fairness, enforceability, missing clauses, defined-term hygiene, or whether the deal is any good. Readability is necessary for an honest contract, never sufficient.
Frequently asked questions
Is my contract uploaded anywhere when I paste it here?
No. Plainly: your text never leaves your browser. Every metric on this page is computed by JavaScript running locally on your device — there is no server that receives, stores, or logs what you paste. You can load the page, disconnect from the internet, and it still works. The optional share link encodes at most the first 800 characters of your text into the link itself, and only if you click the share button.
What is the Flesch-Kincaid grade level?
It is a standard readability formula that estimates the U.S. school grade needed to
understand a text on first reading, from words per sentence and syllables per word:
grade = 0.39 × (words/sentences) + 11.8 × (syllables/words) − 15.59. A grade of
8 reads like a newspaper; 16 or more reads at post-graduate level, which is typical of
unedited contracts.
What is a good readability score for a contract?
On this tool’s 0–100 scale, 70+ means the text is genuinely plain-language; 40–70 is typical professional drafting that a motivated non-lawyer can follow; below 40 is dense legalese most signers will not actually read. Consumer-facing contracts should aim for 60+, roughly a high-school reading level, which several plain-language laws already require for insurance policies and consumer agreements.
Is this legal advice?
No. This tool measures how hard a text is to read — it says nothing about whether the contract is fair, enforceable, or right for you. A perfectly readable contract can still be a bad deal. For anything that matters, have a licensed attorney review the document.
Not legal advice. This tool performs readability analysis only — it does not evaluate the meaning, fairness, or enforceability of any document, and its passive-voice figure is a labeled estimate. Consult a licensed attorney before signing or drafting anything that matters. No liability is accepted for decisions made from these results.