The BDA Dyslexia Style Guide: what every teacher needs to know

Why dyslexia-friendly formatting matters

Roughly 10% of the UK population is dyslexic. In a class of 30, that's likely three pupils who experience some level of visual stress when reading. The wrong font, tight line spacing, or a bright white background can turn a straightforward worksheet into an exhausting task.

The BDA Style Guide exists to address this. First published in 2014 and widely referenced across UK education, it sets out clear, evidence-based rules for making any written material easier to read — not just for dyslexic readers, but for everyone.

As the BDA puts it: “Adopting best practice for dyslexic readers has the advantage of making documents easier on the eye for everyone.”

Fonts

The single most impactful change you can make is your font choice. The BDA recommends a plain, evenly spaced sans serif font. Their suggested options:

• Recommended: Arial, Comic Sans
• Alternatives: Verdana, Tahoma, Century Gothic, Trebuchet, Calibri
• Specialist: OpenDyslexic (a free font designed specifically for dyslexic readers, with weighted bottoms to prevent letter-flipping)

Why sans serif? Serif fonts (like Times New Roman) add small strokes to the ends of letters. For dyslexic readers, these decorations make letters appear more crowded and harder to distinguish. Sans serif fonts keep each letter clean and distinct.

Font size should be 12–14 point as a minimum. Some pupils may need larger — always be prepared to go up rather than down.

Spacing

Spacing is just as important as font choice. Cramped text is one of the biggest barriers for dyslexic readers.

• Line spacing: 1.5 (150%) is the recommended minimum. This gives each line room to breathe and prevents lines from visually merging.
• Character spacing: Slightly increased letter spacing improves readability. The ideal is roughly 35% of the average letter width — enough to separate letters without breaking word shapes.
• Word spacing: Should be at least 3.5 times the character spacing.
• Paragraph spacing: Add extra space after headings and between paragraphs. Dense blocks of text are particularly difficult.

Headings and emphasis

The BDA is very clear on what to avoid:

• No underlining — it makes text appear to run together.
• No italics — they distort letter shapes and reduce readability.
• No block capitals — they eliminate the ascending and descending letter shapes that readers use to recognise words quickly.

Instead, use bold for emphasis. For headings, use a larger font size (at least 20% bigger than body text) in bold, lower case. Boxes and borders can also provide effective emphasis without distorting text.

Layout

How text is arranged on the page makes a significant difference:

• Left-aligned text only — never use full justification. Justified text creates uneven spacing between words, which is distracting for dyslexic readers.
• Line length: 60–70 characters — lines that are too long make it difficult to track back to the start of the next line. Newspaper-style narrow columns should also be avoided.
• Avoid clutter — space content out generously. Dense, cramped layouts are the enemy of readability.
• Break up long documents with sub-headings, and include a table of contents for navigation.
• Avoid starting a sentence at the end of a line — if a sentence begins on the last few characters of a line, it can cause tracking problems.

Colour and backgrounds

This is an area where many teachers are already aware of the basics, but the BDA guidelines go further than “print on coloured paper”:

• Avoid pure white backgrounds. White can appear too dazzling and cause visual stress. Use cream or a soft pastel colour instead.
• Dark text on a light background — not the reverse.
• Avoid red, green, and pink — these colours are problematic for anyone with colour vision deficiency, which affects roughly 8% of males.
• Single colour backgrounds only — patterned or textured backgrounds distract from the text.
• Individual colour preferences vary. Some dyslexic learners find a particular tint works best for them. Where possible, ask the pupil what helps.

Printing

When printing materials for dyslexic pupils, the BDA recommends:

• Matt paper, not glossy — glossy paper causes glare, which increases visual stress.
• Paper thick enough to prevent show-through — text bleeding through from the reverse side creates visual noise that interferes with reading.
• Avoid digital print processes that leave paper shiny.

Writing style

Formatting is only half the picture. The way content is written matters just as much:

• Short, simple sentences in a direct style.
• Active voice rather than passive (“The teacher marked the work” not “The work was marked by the teacher”).
• Avoid double negatives — they increase cognitive load.
• Use bullet points and numbered lists rather than long paragraphs of continuous prose.
• Avoid jargon and abbreviations where possible. If abbreviations are necessary, explain them on first use and provide a glossary.
• Use images, charts, and graphics to break up text and help pupils locate information.

Checking readability

The BDA recommends using readability scores to verify your documents are accessible:

• Flesch Reading Ease: Aim for a score of 70 –80 (on a 100-point scale, where higher is easier).
• Flesch-Kincaid Grade Level: Aim for roughly 5.0, which corresponds to a Year 6 reading level. Achieve this through shorter sentences, not by dumbing down vocabulary.

Most word processors (including Microsoft Word and Google Docs) can calculate these scores automatically.

Digital documents and screen readers

The BDA Style Guide also covers preparing documents for text-to-speech software, which many dyslexic pupils use:

• Put full stops after headings so screen readers pause appropriately.
• Add punctuation after bullet points (semicolons or commas) to create pauses.
• Avoid text in images — screen readers cannot read it.
• Use hyperlinks for navigation in long digital documents.
• Avoid automatic numbering (some screen readers skip it) — use manual numbering instead.
• Offer documents in Word format as well as PDF — Word files are easier to customise for individual viewing preferences.

Quick-reference checklist

Pin this to your classroom wall or save it alongside your planning:

The hard part: applying all this to every worksheet

If you're reading this list and thinking “that's a lot of reformatting” — you're right. Applying BDA guidelines consistently across every worksheet, handout, and assessment is genuinely time-consuming, especially when different pupils need different accommodations.

A pupil with dyslexia might need OpenDyslexic font on a cream background with 1.5 line spacing. Another might need Arial at 14pt on a pale blue background. A third might need all of that plus simplified vocabulary. Multiply that by 30 pupils and it becomes clear why so many teachers default to one-size overlays rather than proper, per-pupil formatting.

That's the problem Adaptify was built to solve.