You don’t need a CFO to model your burn. You need clarity, a few formulas, and a free weekend.
That was my reality. We’d been paying a finance consultant $3,000 a month to send us quarterly models we barely used. So I sat down, opened Excel, and built it myself.
Here’s how to replace the consultant and get more useful numbers than you ever got from their PDFs.
Step 1: Start With Monthly View, Not Annual
Yearly summaries hide volatility. Monthly shows burn rate, MRR churn, hiring spikes. Make a simple table:
- Starting cash
- Revenue (MRR, one off, services)
- Expenses (headcount, infra, tools)
- Ending cash
Now you’ve got a runway calculator.
Step 2: Build From the Bottom Up
Don’t guess. List every SaaS tool. Every hire. Every marketing campaign. Add columns for start month and scaling logic (“+1 SDR in Month 5”).
This makes the model reflect how the business actually runs, not just what looks clean for a pitch.
Step 3: Create Scenario Columns
Base case, stretch case, worst case. Change three inputs:
- CAC
- Churn
- Hiring speed
This gives you a living model, not a fixed story.
Step 4: Link Revenue to Inputs
No hand-waving. Your revenue should be driven by inputs:
- Leads generated
- Conversion rate
- Average contract value
If you can’t model it, you probably can’t manage it.
Step 5: Use It Weekly
This isn’t a one-and-done spreadsheet. Use it in standups. Share it with co-founders. Flag when hiring plans or MRR deviates.
The goal isn’t to be perfectly accurate. It’s to spot drift before it becomes risk.
Bonus for Pros: Use This Google Sheets Template
Template (Credits goes to anonymous champ, not me)
Google Sheets also forces you to collaborate. And it lets others leave comments, not “final_v6_NEW.xls” attachments.
A $3k consultant gives you a quarterly deck. Your Excel model gives you control. It doesn’t need to be pretty. It needs to be true.
And when you’ve built it yourself, you actually trust it. That’s what keeps you in business.
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