How many slides a demo day pitch deck needs
Start with the arithmetic, because it settles most of this. Kevin Hale's YC guide gives each company 2 minutes and 30 seconds and suggests only about 5 to 7 slides. That's a slide every 21 to 30 seconds. Slidebean's guide allows 3 minutes and 10 or 15 slides, and 15 slides in 3 minutes leaves 12 seconds each. PitchGrade lands in between at seven to ten.
I side with the low end. Ralston's reason is the one that matters: "An audience cannot read a slide AND listen to you simultaneously." At 12 seconds a slide, nobody finishes reading before the next one arrives, and you've spent your whole slot competing with your own deck.
Longer slots don't change this much. Alchemist's demo day is 5 minutes and it still calls great pitches "movie trailers, not movie summaries." Give each slide more talking time before you add another slide. And check your own programme's slot before you build anything, because these numbers vary by accelerator and some of them are years old.
What goes on each slide
Build this from Ralston's advice to find your "vertebrae": the three or four points you want the room to remember. Write the talk first, then draw slides for it. His warning is blunt: "Do not build a slide deck and then tell a story that supports your slides." For seven slides, I'd use this order:
- One-liner: what you do in plain words. Ralston's example is "We deliver groceries to customers in their homes." Mukund Mohan, who ran 10 demo days, says the first line decides whether people keep listening.
- Traction: your best number, early. 500 Global says to get revenue and growth into the first 30 seconds, and Slidebean also moves traction up to second place. More on charting it in my traction slide guide.
- Problem: one line. If the setup runs long, people reach the halfway point without knowing what you do.
- Product: who uses it and what changes for them. One image and a short label.
- Market: a bottom-up figure, price times potential customers, shown as a single sum on the slide.
- Team: only the credentials that make you the right people for this problem.
- Close: your three or four vertebrae, what you're raising, and how to reach you.
What if you don't have traction yet?
Most demo day templates assume you've got a growth curve. Plenty of companies don't, and Ralston is clear this isn't fatal: "Many startups have successfully presented their companies pre-traction," though you then lean harder on your story, credentials and vision.
In design terms, keep slide two but swap what's on it. Put the strongest proof you actually have there: a signed pilot, a waitlist, a technical result, a founder who has solved this problem before. It should get the same treatment as a traction chart, with one big figure or fact and a short label. Then let the team slide carry more weight.
One thing I wouldn't do is dress up a small number. If a chart looks thin, drop the chart and state the fact in words.
How to design demo day slides for a big room
Hale wrote that the YC room held over 500 people, and "they can't all sit in the front row." His test is slides that "old people sitting in the back row with bad eyesight can read." Yours may be a smaller room, but the design logic holds. You're designing for the worst seat, which means a different set of rules from a deck someone reads on their phone.
- Set a type floor. Alchemist suggests nothing smaller than 60pt for bullets, and it's the only firm figure I found. Treat it as your minimum for body text, with headlines larger.
- Cap the words. Ralston says more than 7 words is likely too many. At 60pt, the slide will enforce this for you.
- Put key text at the top. Hale notes it's easier to read from the back of the room, since heads in front block the lower part of the view.
- Write the takeaway as the title. Alchemist's example is "Our Market is Gigantic" rather than "Market", and it wants each slide understood in 10 seconds.
- Replace screenshots. Hale calls them "almost always illegible, complex, and non-obvious." Crop to the one element that matters, or redraw it as a simple diagram.
- Avoid cumulative charts, which Ralston says "always cause immediate suspicion." Plot monthly figures and label the start and end values large.
- Use strong contrast. Light grey caption text on white disappears on a washed-out projector. Hale's example of what not to do hid its key explanation in light grey at the bottom of the slide.
Should a demo day pitch deck include a demo or video?
The guides split here. Ralston says demos "seldom work" and videos are "almost never a good idea," because investors want to see you perform. Flowjam suggests a 10 to 15 second clip, and Alchemist accepts a short pre-recorded demo alongside the deck.
My view: no live demo. If the product can only be understood in motion, use a muted, looping clip of a few seconds, embedded in the file, and keep talking over it. The clip supports what you're saying and you stay the thing people watch.
Prepare for the slides to fail
Mohan saw presenters freeze when they lost their slides, and says investors took that as a sign of how a founder might handle a crisis. His advice is to use the deck "as a prop alone." So rehearse the full pitch once with the screen off.
Then ask your organiser four dull questions: who supplies the laptop, what aspect ratio the screen is, which file format they want, and when the deadline is. Formats differ. Alchemist requires 16:9 and PowerPoint only and asks for near-final decks by the on-stage rehearsal. If you're not presenting from your own machine, a custom font can be swapped for a default, which will wreck your line breaks. Embed your fonts and bring a PDF as backup. Alchemist also advises against heavy animation, and I'd go further and use none.
Build the second deck before demo day
Your stage slides will make no sense without you talking over them, and the people you impress will ask for something to read. Flowjam makes this split explicit, with 6 slides on stage and 15 to send. PitchGrade recommends a 10 to 12 slide investor deck for afterwards.
I'd aim for 10 to 12. Use the same brand and the same headline numbers, then add the words your voice supplied on stage, plus competition, business model and use of funds. That's the deck I describe in my ten-slide structure. Have it ready the day before, because the warm replies arrive straight after you step off stage and you won't have time to build it then.
If demo day is close and you'd like both decks done properly, here's how I work, what it costs and how fast I can turn it round. First drafts land 48 hours after an approved brief, and you get native, editable files.