The Perfect Length for a Startup Pitch Deck
What every investor expects to see when you show them your slides.
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5 min read
Jul 31, 2025
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Photo by Teemu Paananen on Unsplash
A startup accelerator brought me in for an afternoon to work with some of its companies on building pitch decks. The very first founder I met sat down, opened his laptop, pulled up a half-built deck, and immediately asked: “I’m already at 13 slides, but I hear you don’t want more than ten. Is it OK to have more than 10? If so, what’s the maximum number of slides it can be?”
At least half the other founders I met asked a similar question.
“Is 12 slides too many?”
“Is this enough slides?”
“What slides do I need?”
For what it’s worth, I also hear the same type of question dozens of times every school year from my students. Whenever I assign any sort of writing assignment, the first question my undergraduates always ask is: “How long does it have to be?”
And every time I get asked the question, whether it’s one of my students trying to size up the amount of work required for an essay or a founder trying to figure out the formula for a perfect pitch deck, I roll my eyes. Asking “How long does it have to be?” is never a good sign, because it’s not really a question about length. It’s a question about sufficiency. It’s a question about thresholds. It’s a question about doing just enough to check a box, and it’s always the wrong way to think about building something important.
I didn’t tell the founder that. Not directly. I just smiled and said, “As long as it needs to be to get to the next stage in the fundraising process.”
I realize it’s a frustrating answer, but it’s also the only correct answer. After all, that’s what a pitch deck is for. It’s not a product. It’s not an essay. It’s not your shot at going viral on LinkedIn. It’s part of a process. It’s a sort of test to show whether you understand how to tell a compelling story to someone who hears fifty of them a week. And if your first question is about length, then you’re thinking like a student chasing a grade instead of a founder chasing an opportunity.