Score easy (≤2 syllable) vs. hard (3+ syllable) words across a 100‑word sample to estimate grade level.
Built and maintained by Paul Clark, Redmoon Software · Last verified · Sources
Use Linsear Write for quick estimates on technical manuals or training material where you need a single grade level fast. Originally designed for Air Force technicians to grade their own writing, it remains a useful sanity-check formula.
Linsear Write splits the difference between Gunning Fog (which heavily penalises long words) and Flesch–Kincaid (which weights sentence length). It is a useful third opinion when Fog and FK disagree.
Linsear Write was created by the US Air Force as a fast readability check for technical manuals.
It weights "easy" (1–2 syllable) words and "hard" (3+ syllable) words differently within a 100-word sample.
Best used as a quick sanity check rather than a definitive readability score.
The US Air Force developed Linsear Write to help airmen evaluate technical writing without specialist training.
Words of two syllables or fewer count as easy, and words of three or more syllables count as hard (long). The proportion of long words is the main driver of the grade score, so dense polysyllabic vocabulary pushes the level up quickly.
It is designed around a 100-word sample. Scoring a much shorter passage makes the result noisy, so paste at least a full paragraph or two for a stable estimate.
Both estimate a US grade level, but Linsear Write splits words into a simple easy/hard bucket rather than averaging syllables per word. It tends to track Flesch-Kincaid closely for technical and instructional prose, which is what the Air Force originally designed it for.
Input
100-word sample with 70 easy and 12 hard words across 9 sentences.
Output
Linsear Write grade level: ~8.5 — 8th–9th grade.
Easy words (1–2 syllables) score 1; hard words (3+ syllables) score 3. The weighted total is divided by sentences then halved, giving grade ~8.5.
Linsear Write, developed for US Air Force technical manuals, works on a 100-word sample and separates words into two classes: those of two syllables or fewer, and those of three or more. Easy words count once, hard words count three times. That weighted total is divided by the number of sentences, then halved — with an extra adjustment applied when the provisional result is 20 or below.
The triple weighting on polysyllables is the point of the formula. It is more aggressive than Fog's equal weighting and more aggressive than Flesch's coefficient, which makes Linsear Write the harshest of the classic indices on technical vocabulary.
That aggression is appropriate for its origin — a maintenance manual that a reader must follow exactly — and often too harsh for general writing, where a few long words are simply the right words.
The method behind this tool, so you can check it rather than take it on trust.
Klare, G.R. (1974–75). “Assessing Readability.” Reading Research Quarterly, 10(1), 62–102.
Surveys the formula family including Linsear Write, which was developed for US Air Force technical manuals.
Classic 0–100 readability score.
Readability scoresU.S. grade level for your text.
Readability scoresPenalises complex (3+ syllable) words.
Readability scoresHealth & medical text grade level.