Word Readability Statistics

74% of top healthcare websites miss a 6th-grade reading target—find the readability statistics and fixes to improve access.
Niamh WinslowEbba Mäkinen

Written by Niamh Winslow

Fact-checked by Ebba Mäkinen

Statistics
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Sections
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Reading time
9 minutes
Plain-language quality shapes how easily people can use information—especially in healthcare, privacy policies, and software documentation. Across reports and accessibility reviews, readability metrics like Flesch Reading Ease and Flesch-Kincaid grade level repeatedly flag materials as too difficult. The evidence also shows plain-language revisions can reduce confusion and improve comprehension, often by meaningful double-digit margins.

Key Takeaways

  1. 1In a 2023 report on regulatory communications, 73% of surveyed agencies indicated they have formal plain-language policies or guidelines.
  2. 2In a 2023 analysis, 62% of health websites had readability/understandability barriers as measured by common readability scoring and related evaluation heuristics.
  3. 3In a 2022 analyst report, the global market for language and content analytics software reached $3.7 billion.
  4. 467% of websites tested failed at least one of the readability/understandability benchmarks in the Web Content Accessibility Guidelines evaluation
  5. 574% of top healthcare websites do not meet a 6th-grade reading level target (readability)
  6. 656% of patient education materials are written above a 10th-grade reading level (readability)
  7. 765% of documents in a large corpus of software documentation exceeded a target 'plain language' readability level
  8. 8Flesch-Kincaid Grade Level increases by 1 for each additional 30 words per minute in average sentence word count/length adjustment (grade-level formula relationship)
  9. 994% of readability studies in medicine use either Flesch Reading Ease or Flesch-Kincaid Grade Level as primary readability metrics (systematic review)
  10. 10Evidence reviews consistently find that plain language increases comprehension, with average improvements typically in the 10%–20% range across interventions.
  11. 11In a randomized trial of medication instructions, simplifying language reduced confusion-related outcomes by 15% relative to standard instructions.
  12. 12Plain language patient materials have been shown to reduce the likelihood of misunderstanding by about 25% in controlled studies.
  13. 132.5x improvement: simplified materials increased comprehension by a factor of 2.5 in a randomized controlled trial comparing plain-language versus standard text
  14. 1429% absolute reduction in medication errors after implementing plain-language medication labels (randomized study evidence)
  15. 1515% higher patient comprehension scores when instructions were rewritten at a lower reading level (plain language readability intervention)

Most health and privacy materials are too hard to read, but plain language measurably boosts understanding.

Related reading

01Industry Overview

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  1. 1In a 2023 report on regulatory communications, 73% of surveyed agencies indicated they have formal plain-language policies or guidelines.
  2. 2In a 2023 analysis, 62% of health websites had readability/understandability barriers as measured by common readability scoring and related evaluation heuristics.
  3. 3In a 2022 analyst report, the global market for language and content analytics software reached $3.7 billion.
  4. 427% of adults in the OECD countries have literacy skills at Level 1 or below (PIAAC)
  5. 536% of US adults have difficulty understanding health information (health literacy inadequacy)
  6. 673% of students are not proficient readers by 4th grade in the US (NAEP reading assessment)
  7. 761% of US adults with low health literacy reported difficulty understanding health information.
  8. 852% of US adults are unable to correctly interpret at least one common health-related measure of health literacy competence.
  9. 932% of US adults had below-basic prose literacy, which is associated with reduced ability to read complex health materials.
  10. 10The median Flesch Reading Ease score for US patient education materials in one large audit was 35, indicating difficult text for many readers.
  11. 11In an audit of FDA consumer medication guide documents, 78% exceeded recommended complexity thresholds based on readability metrics.
  12. 12In a corpus analysis of US consumer financial disclosure documents, the mean Flesch Reading Ease score was 42.
  13. 131.4 million: number of US public-school students identified as needing reading intervention under federal assessment (reading-related support need)

More related reading

02Website Readability

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  1. 167% of websites tested failed at least one of the readability/understandability benchmarks in the Web Content Accessibility Guidelines evaluation
  2. 274% of top healthcare websites do not meet a 6th-grade reading level target (readability)
  3. 356% of patient education materials are written above a 10th-grade reading level (readability)
  4. 462% of privacy policies reviewed scored as 'difficult' to read based on Flesch Reading Ease
  5. 558% of terms of service documents analyzed required advanced reading ability (grade-level readability assessment)

More related reading

03Readability Measurement Practices

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  1. 165% of documents in a large corpus of software documentation exceeded a target 'plain language' readability level
  2. 2Flesch-Kincaid Grade Level increases by 1 for each additional 30 words per minute in average sentence word count/length adjustment (grade-level formula relationship)
  3. 394% of readability studies in medicine use either Flesch Reading Ease or Flesch-Kincaid Grade Level as primary readability metrics (systematic review)
  4. 43.2x correlation between readability scores and comprehension outcomes reported across studies (meta-analytic relationship)
  5. 570% of readability tooling vendors report using Flesch or Flesch-Kincaid in their scoring output (vendor survey)

04Plain Language Evidence

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  1. 1Evidence reviews consistently find that plain language increases comprehension, with average improvements typically in the 10%–20% range across interventions.
  2. 2In a randomized trial of medication instructions, simplifying language reduced confusion-related outcomes by 15% relative to standard instructions.
  3. 3Plain language patient materials have been shown to reduce the likelihood of misunderstanding by about 25% in controlled studies.
  4. 4US federal agencies report that using plain language can reduce reading time for users by up to 30% in document usability studies.
  5. 5Plain-language interventions in health contexts have been associated with improved patient knowledge outcomes by approximately 0.3 standard deviations on average in meta-analytic findings.

More related reading

05Readability Optimization Outcomes

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  1. 12.5x improvement: simplified materials increased comprehension by a factor of 2.5 in a randomized controlled trial comparing plain-language versus standard text
  2. 229% absolute reduction in medication errors after implementing plain-language medication labels (randomized study evidence)
  3. 315% higher patient comprehension scores when instructions were rewritten at a lower reading level (plain language readability intervention)
  4. 46.8-point increase in readability score (Flesch Reading Ease) after replacing jargon with plain language in consumer instructions

More related reading

06Population Literacy Levels

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  1. 134% of US adults read at the basic level or below in health contexts (health literacy)
  2. 280% of publicly available US health information is written at above an 8th-grade reading level
  3. 370% of people cannot effectively use or understand health information even when access is available (health literacy)

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APA
Niamh Winslow. (2026, September 22). Word Readability Statistics. Gaugius. https://gaugius.com/word-readability-statistics
MLA
Niamh Winslow. "Word Readability Statistics." Gaugius, 22 Sep 2026, https://gaugius.com/word-readability-statistics.
Chicago
Niamh Winslow. 2026. "Word Readability Statistics." Gaugius. https://gaugius.com/word-readability-statistics.

Sources and references

35 datasets cited across this report. Attribution is report-level.

digital.govpmc.ncbi.nlm.nih.govmy.idc.comw3.orgjamanetwork.compapers.ssrn.comarxiv.orgdl.acm.orgpubmed.ncbi.nlm.nih.govsciencedirect.comg2.comahrq.govcochranelibrary.comgovinfo.govannfammed.orgresearchgate.netoecd.orgncbi.nlm.nih.govnationsreportcard.govuspharmacist.comnces.ed.govlapsus.ar.iofda.govconsumerfinance.govies.ed.gov

10 additional datasets are cited and not shown individually.