How to improve your readability score

Eight tactical edits that move every readability formula — Flesch-Kincaid, Flesch Reading Ease, Gunning Fog, SMOG, Coleman-Liau, ARI — with worked before-and-after examples. No theory beyond the bare minimum. The goal is edits you can make in the next ten minutes.

Step 1: Diagnose before you edit

Score your text against all six formulas first. The pattern of scores tells you what to fix. If your Flesch-Kincaid is high but Coleman-Liau is fine, sentence length is your problem. If both are high, vocabulary is doing the damage. If SMOG runs noticeably above Flesch-Kincaid, your text has too many 3+ syllable words.

• High Flesch-Kincaid + low Coleman-Liau → sentence-length problem. Skip to tactic 1.
• High Flesch-Kincaid + high Coleman-Liau → vocabulary problem. Skip to tactic 2.
• SMOG > Flesch-Kincaid + 1.5 → too many complex words. Tactics 2 and 3.
• High Gunning Fog only → jargon-heavy. Tactic 2 with extra attention to nouns.
• Everything is high → all tactics, in order.

Use the calculator to confirm; the sentence-level highlighting will mark the offenders for you.

Tactic 1: Cut sentences over 25 words

Long sentences are the single most common readability problem in professional writing. Anything over 25 words almost always benefits from being two sentences. The threshold isn't arbitrary — it's roughly the limit of working memory for the average reader.

The pattern that produces too-long sentences is almost always a chain of subordinate clauses. When you find one, look for the conjunction in the middle ("and," "but," "which," "because," "where") and split there.

Before: The implementation of the new policy, which was approved by the board last quarter after extensive consultation with stakeholders across the organisation, will be rolled out in three phases beginning next month and concluding by year-end.

After: The board approved the new policy last quarter after extensive consultation with stakeholders. Rollout will happen in three phases — starting next month, finishing by year-end.

Word count went from 41 to 25 across two sentences. Flesch-Kincaid drops by roughly 4 grades.

Tactic 2: Prefer one-syllable verbs

Vocabulary substitution is the strongest editing lever for every readability formula. The Flesch Reading Ease formula weighs syllables-per-word at roughly 80× the weight of sentence length — meaning one syllable saved per word moves the score more than two words cut per sentence.

Build a list of habitual swaps:

• utilise → use
• implement → start, set up, do, use
• facilitate → help, run, lead
• demonstrate → show
• communicate → tell, say, write
• investigate → look at, check, study
• determine → decide, work out, find
• commence → start, begin
• terminate → end, stop, fire
• approximately → about, around, roughly
• subsequent to → after
• in the event that → if

Five swaps in a 200-word passage typically drops the grade level by 1 to 2 points across every formula.

Tactic 3: Replace nominalisations with verbs

A nominalisation is a verb that has been turned into a noun: decision from decide, implementation from implement, analysis from analyse. Nominalisations almost always require a weak verb to support them ("make a decision," "perform an analysis"), which adds words and syllables for no semantic gain.

• made the decision to → decided to
• perform an analysis of → analyse
• provide assistance with → help with
• reach an agreement on → agree on
• take into consideration → consider
• have a discussion about → discuss

Each substitution typically saves 2 to 4 syllables and 2 to 3 words. Apply the pattern across a document and the cumulative effect on grade level is dramatic.

Tactic 4: Cut filler adverbs and intensifiers

Words like very, really, quite, rather, basically, essentially, fundamentally, clearly, obviously, simply rarely add meaning. They add syllables and signal hedging. Delete them as a default; restore only when the meaning genuinely changes.

Before: The data clearly demonstrates that this approach is essentially superior to existing methods.

After: The data shows this approach beats existing methods.

Word count: 14 → 9. Syllables saved: 8. Same meaning.

Tactic 5: Strong verbs over weak verb + adjective

Many sentences hide a strong verb behind a weak verb plus a modifier. "Walked quickly" → "hurried." "Said angrily" → "snapped." "Made better" → "improved." This is the rule that makes Hemingway prose famously high-scoring on readability formulas: a single decisive verb does the work of a phrase.

• was able to → could
• has the ability to → can
• is in agreement with → agrees with
• made an improvement to → improved
• walked quickly → hurried
• looked carefully at → examined / inspected

Tactic 6: Prefer active voice

Active voice is shorter and more direct than passive. It usually saves 1 to 3 words per sentence and removes the syllabic overhead of "was/were + past participle + by."

Passive: The proposal was reviewed by the committee and was approved unanimously.

Active: The committee reviewed the proposal and approved it unanimously.

Word count: 12 → 10. Sentence is more direct, attributes action to the actor, and reads faster.

Tactic 7: Read it aloud

This is the test no formula can replace. Read your text out loud — preferably to another person, or recorded back to yourself. Every place you stumble is a place a reader will stumble. Every sentence that runs out of breath is too long. Every word your mouth can't quite produce is too complex.

Reading aloud catches:

• Sentences that should be split (you ran out of breath)
• Words that don't work (you hesitated)
• Awkward repetitions (your ear noticed)
• Wrong rhythm (the sentences feel monotonous)

If you're optimising professional writing for any audience, this single technique outperforms any algorithmic check. The formulas confirm what your ear already knows.

Tactic 8: Vary sentence length deliberately

Average sentence length is what readability formulas measure, but rhythm is what readers feel. The most engaging prose mixes long and short sentences on purpose. Long sentence to develop an idea. Short one to land it.

The technique: after every two long sentences (15+ words), write one short one (under 10 words). The contrast does the rhetorical work. Hemingway scores famously well on Flesch Reading Ease (typically 80–95) precisely because he varied length aggressively — most of his sentences are very short, with occasional longer ones for emphasis.

A practical editing workflow

1. Score your draft. Note which formula is highest.
2. Use the diagnostic in step 1 to identify the dominant problem (sentence length vs vocabulary).
3. If sentence length: scan for sentences over 25 words, split each one (tactic 1).
4. If vocabulary: scan for 3+ syllable words, swap where possible (tactics 2 and 3).
5. Pass through cutting filler (tactic 4) and weak verbs (tactic 5).
6. Re-score. The gap should have closed by 1 to 3 grade levels.
7. Read aloud. Fix anything that makes you hesitate.
8. Re-score one more time. You're done when the score matches your audience target.

Most professional writers can drop a 12th-grade draft to 8th grade in 20 minutes using this workflow. The improvement compounds across documents — the habits become the writing style.

Frequently asked questions