Most founders think they need a CFO when they hit a certain revenue number. That's backwards. You need a CFO when the financial questions start slowing down your decisions.
If you're asking questions like "how much runway do we actually have?", "what does our unit economics look like at scale?", or "what financial story do we tell investors?" — and the answers take you more than 15 minutes to produce — you need financial leadership.
A fractional CFO costs $1,500-5,000/month versus $300K+ for a full-time CFO. You get the strategic thinking without the overhead. The engagement scales with your needs: monthly retainer for ongoing work, or project-based for specific deliverables like a fundraise model.
What you shouldn't expect: a fractional CFO to also handle your day-to-day bookkeeping and AP. That's a different service. The best fractional engagements pair strategic CFO work with a competent bookkeeper or accounting team — whether that's internal or also fractional.
I've been on both sides of this. As VP Finance at DialSource (now Conquer), I built the models, reported to the board, and led the finance function. At Kranz Consulting, I was the fractional resource for VC-backed startups. What matters most is that the person understands your business model deeply, not that they're sitting in your office 40 hours a week.
This post is for general educational purposes only and does not constitute tax, legal, accounting, or investment advice. Consult a qualified professional for your specific situation. Content reflects the author's understanding as of the publication date; rules, rates, and interpretations may change.