The short answer to how many words per slide is: fewer than you think. For most content slides, aim for roughly 15 to 30 words, and rarely go past 40. That is not an arbitrary aesthetic rule. It follows from a simple fact about how audiences process a talk: people cannot comfortably read one thing while listening to another, so every extra sentence on the screen competes with what you are saying.

This guide explains where common rules of thumb come from, gives concrete limits for different kinds of slides, and shows where the rest of your material should go instead.

Why the number of words on a slide matters#

A typical presenter speaks at around 130 words per minute. Silent reading is much faster: a 2019 meta-analysis by Marc Brysbaert put the average adult reading speed for English non-fiction at roughly 240 words per minute. That gap creates a predictable problem. When a dense slide appears, the audience reads ahead of you, finishes early, and then either waits or tunes out. When you read the slide aloud word for word, they hear the same sentence twice and stop listening to either.

Short slides avoid both failure modes. A slide with a headline and three short points takes a few seconds to scan, and then attention comes back to you. The slide supports the talk instead of replacing it.

How many words per slide: limits by slide type#

One number does not fit every slide. These ranges work well in practice:

• Title and section slides: 3 to 10 words. A clear title and, at most, a one-line subtitle.
• Content slides: 15 to 30 words. A headline that states the point, plus two to four short supporting lines.
• Quote slides: up to 25 words for the quote itself. Longer quotes are hard to read from the back of the room; trim them or paraphrase.
• Data and table slides: keep the prose to a short headline that says what the numbers mean, for example "Repeat customers drove most of Q3 growth". Let the chart or table carry the detail, and keep tables small enough to read from a distance.
• Closing slides: one call to action or a short summary, not a recap of every section.

If a slide keeps growing past 40 words, it is usually two slides pretending to be one.

Common rules of thumb, and where they come from#

You will see a few rules quoted again and again:

• The 6x6 rule: no more than six bullet points, each no longer than six words. It is a useful ceiling, not a target. Thirty-six words of bullets is still a lot to absorb.
• The 10/20/30 rule: popularised by Guy Kawasaki, it suggests about 10 slides, 20 minutes and no font smaller than 30 points. The font size is the clever part: at 30 points, you physically cannot fit a paragraph on a slide.
• One idea per slide: the most durable rule of all. If you can summarise the slide in one sentence, the headline should be that sentence.

All three point in the same direction. Keep slide text short and let your voice do the explaining.

Font size sets a natural limit#

Word count and font size are linked. The larger the type, the fewer words fit, and the easier the slide is to read from the back of the room. Before you decide how much text to keep, check the minimum readable size for your room with the presentation font size calculator. If your content only fits at a size the back row cannot read, the slide has too many words, not too little space.

Where the rest of your words should go#

Cutting slide text does not mean cutting content. It means putting it in the right place:

• Speaker notes hold the full explanation, examples and numbers you want to mention. You read them; the audience does not.
• A handout or follow-up document carries the detail people may want to revisit later.
• Additional slides are cheaper than crowded ones. Splitting a dense slide into two usually adds clarity without adding much time.

If you are planning a talk, it helps to work out the length first. The speech time calculator converts a script into speaking time, and the slides per minute calculator suggests how many slides that time can support. Together they keep you from compressing a 20-minute talk into ten crowded slides.

A quick editing pass for wordy slides#

When a slide feels heavy, go through it in this order:

1. Rewrite the headline as a full sentence that states the conclusion.
2. Delete any bullet that only repeats the headline.
3. Cut each remaining bullet to a phrase, not a sentence.
4. Move examples, caveats and numbers you will say aloud into the speaker notes.
5. If more than four bullets remain, split the slide.

Writing slides in Markdown makes this pass faster, because every slide is just a few lines of text. In the Markdown to slides editor, a line containing three dashes starts a new slide, so splitting a crowded slide is a one-line change, and anything after a Note: line becomes speaker notes rather than slide text.

Counting words on your own slides#

A rough count is enough. Read the slide aloud at your normal pace: if it takes more than about ten seconds, the audience will spend that long reading it while you talk. That is your signal to shorten it or split it. Title and section slides should take two or three seconds; content slides rarely more than ten.

What this can't do yet#

ToSlides helps you plan and write lean slides, but it is not a full design suite: it ships four themes, with no animated transitions, motion graphics or drag-and-drop layout canvas. The planning calculators and the Markdown editor are free in the browser without an account; AI deck generation requires signing in with an EndTo account and uses credits.