Stop building your own financial model
Infinia ยท
There's a belief in startup culture that's treated as gospel: a great founder builds their own financial model.
You'll hear it from investors. "I want to see that the founder knows the business cold." You'll hear it from other founders, a little proudly. "I built every tab myself."
I think it's wrong. At $1M to $5M ARR, with a raise or a board meeting coming, building your own model is one of the worst uses of your time.
Some of you are nodding. Some of you have already decided I don't understand startups. Stay with me, because the argument is narrower than it sounds.
Knowing your numbers is not the same as building them
Investors are right that you need to know your numbers cold. You should be able to say your runway, retention and CAC payback in one sentence each, without opening a laptop.
But "know" and "build" are different jobs.
A public company CEO knows their numbers cold. Nobody expects them to build the model. They have a CFO who builds it, defends it, and tells them what it means. The CEO's job is to understand it well enough to make decisions and answer hard questions.
Somewhere along the way, startup culture decided that founders should do both. That made sense at $200K ARR, when the model was ten rows and a guess. It stops making sense when the model has to survive a Series A partner's analyst.
What actually happens when founders build it
The raise is eight weeks out. The founder blocks off weekends to rebuild the model. They're good at it, because founders are good at most things. But it isn't their craft.
So the model ends up with three problems.
It's optimistic. Not dishonest, just optimistic. Founders believe in their company, and that belief leaks into every assumption. Churn improves every quarter. Hiring happens on schedule. Sales cycles shorten. Investors have seen hundreds of these, and they discount them on sight.
It doesn't tie out. Runway in the model doesn't match the bank balance. ARR in the model doesn't match ARR in the deck. Nobody notices until an investor does.
It cost the founder the eight weeks that mattered most. Those weekends could have gone to customers, the product, or the three investor relationships that would have made the raise easy.
The founder comes out of it proud of the spreadsheet and behind on everything else.
"But I need to understand my business"
This is the strongest counterargument, and it's half right.
Yes, building a model forces you to understand how your business works. That's valuable. Every founder should do it once, early.
But there's a difference between understanding your business and maintaining a 14-tab spreadsheet before every board meeting. The first is leadership. The second is a job, and it belongs to someone whose job it is.
If the only way you understand your numbers is by building them yourself, that's a sign you don't trust anyone else's version. That's a hiring problem, not a virtue.
"But I can't afford a CFO"
Correct. At $2M ARR, you probably can't justify a $250K full-time CFO, and you shouldn't try.
But the choice isn't between doing it yourself and hiring a full-time executive. It's between doing it yourself and giving one person ownership of the numbers, part-time, for a few days a month.
That person builds the model. You challenge it. They defend it. You understand it well enough to answer every question an investor asks. That's the right division of labor at this stage.
The founders who'll hate this
I know who disagrees with this post, because I've heard the arguments.
Some founders genuinely love the model. It's how they think, and it's where they do their best strategic work. If that's you, keep building it, but get someone else to check it before an investor does.
Some investors want to see the founder's fingerprints on the numbers. Fair. They'll see them in how you answer questions, not in who typed the formulas.
And some will say this is what an introduction service would say. That's fair too. So judge the argument, not the messenger.
The test
Before your next raise or board meeting, ask yourself one question:
If an investor's analyst rebuilt my model from scratch, would their numbers match mine?
If you're confident they would, ignore this post.
If you aren't sure, the answer isn't more weekends in the spreadsheet. It's giving the spreadsheet to someone who will own it, and getting your weekends back for the work only you can do.
Know your numbers. Stop building them.
Infinia introduces founders to fractional CFOs who own a number, not a calendar. One introduction, free.