Introduction
A fractional CFO (Chief Financial Officer) is a senior financial executive who works with a company on a part-time or ongoing basis, delivering the same strategic financial leadership as a full-time CFO without permanent employment.
Unlike accountants or finance consultants, a fractional CFO integrates into the executive team. They own financial strategy, guide decision-making, and build the financial infrastructure required for sustainable growth.
Key distinctions
Fractional CFO vs Full-Time CFO
Fractional CFOs provide the same strategic expertise as full-time CFOs, but with flexible engagement models and significantly lower cost.
Fractional CFO vs Interim CFO
Interim CFOs step in full-time for a defined period during transitions. Fractional CFOs are long-term, part-time partners designed for ongoing financial leadership.
Fractional CFO vs Controller or Accountant
Controllers and accountants focus on historical reporting and compliance. Fractional CFOs focus on forward-looking strategy, capital planning, and financial decision-making.
Fractional CFO vs Consultant
Consultants advise. Fractional CFOs execute. They own financial outcomes and operate as part of leadership.
In practice:
A SaaS company approaching Series A might engage a fractional CFO for 10 to 20 hours per week to build financial models, implement reporting systems, manage burn, and support investor conversations, all without hiring a full-time CFO too early.
What Does a Fractional CFO Do?
The scope of a fractional CFO depends on company stage and complexity, but their work typically falls into five core areas:
Financial Strategy and Planning
- Build financial models and long-range forecasts
- Translate business strategy into financial plans
- Guide pricing, margin optimization, and unit economics
- Support strategic decision-making with data-driven insights
Cash Flow and Capital Management
- Manage burn rate and runway
- Optimize working capital and cash flow
- Plan capital allocation across growth initiatives
- Ensure the company can scale without liquidity risk
Financial Infrastructure and Reporting
- Implement scalable financial systems and processes
- Design dashboards and KPIs for leadership and boards
- Improve accuracy, timeliness, and clarity of reporting
- Establish controls that grow with the business
Fundraising and Investor Readiness
- Prepare financial materials for fundraising
- Support diligence processes and investor questions
- Build credibility with venture capital, private equity, and lenders
- Align financial narratives with growth strategy
Team Leadership and Enablement
- Lead or mentor finance and accounting teams
- Partner closely with the CEO, COO, and other functional leaders
- Bridge strategy and execution across departments
Benefits of Hiring a Fractional CFO
For most growing companies, the choice is not between a fractional CFO and a full-time CFO. It is between getting senior financial leadership now or operating with financial blind spots.
Key benefits
Executive-level expertise at a fraction of the cost
Access senior financial leadership without the $300,000 to $500,000+ cost of a full-time CFO.
Improved decision-making
Replace intuition-based decisions with financial clarity and confidence.
Faster fundraising and stronger outcomes
Companies with experienced financial leadership raise capital more efficiently and on better terms.
Flexible engagement that scales with growth
Increase or decrease involvement as business needs evolve.
Reduced financial risk
Early identification of risks prevents costly surprises.
When Should a Company Hire a Fractional CFO?
A fractional CFO is most valuable when a company is experiencing:
- Rapid growth that outpaces existing financial systems
- Preparation for fundraising at Seed through Series C
- Increasing burn rate and runway concerns
- Complex revenue models or pricing decisions
- Investor or board pressure for stronger reporting
- A CEO spending too much time managing finance instead of growth
From a fund perspective, fractional CFOs can be deployed across portfolio companies to improve capital efficiency, reporting consistency, and valuation readiness.
How Much Does a Fractional CFO Cost?
Fractional CFO pricing varies based on experience, company size, and engagement scope:
- Hourly rates: $200 to $500+ per hour
- Monthly retainers: $10,000 to $25,000+
- Project-based engagements: $15,000 to $75,000+
While this represents a meaningful investment, the ROI is typically realized through improved cash management, faster fundraising, stronger margins, and better strategic decisions.
Fractional CFO vs Alternative Solutions
Role | Strategic Scope | Engagement Model | Best For |
Fractional CFO | Financial strategy and leadership | Part-time, ongoing | Scaling companies |
Interim CFO | Full financial leadership | Full-time, temporary | Transitions or crises |
Controller | Financial operations | Full-time | Day-to-day accounting |
Accountant | Compliance and reporting | Ongoing | Historical financials |
Consultant | Advisory | Project-based | Narrow initiatives |
Why Choose Size.vc for Fractional CFO Leadership
Most fractional finance providers operate as solo consultants or accounting firms extending their services. Size.vc takes a fundamentally different approach.
Our model is designed for founders and funds who need real financial leadership, not just reporting support.
The Size.vc approach
- Access to world-class CFO talent with experience scaling high-growth companies
- Deep understanding of venture-backed business models and investor expectations
- Flexible deployment across individual companies or entire portfolios
- Results-driven execution focused on enterprise value creation
Get Started with Fractional CFO Leadership
Financial leadership is a growth unlock, not a luxury.
If your company is scaling, fundraising, or facing increasing financial complexity, a fractional CFO can provide the clarity and confidence needed to move forward.
Book a consultation today to connect with Size.vc and get matched with a fractional CFO who can help architect your financial future.
Frequently Asked Questions
What is a fractional CFO?
A fractional CFO is a senior financial executive who provides strategic financial leadership on a part-time basis, helping companies scale without hiring a full-time CFO.
How is a fractional CFO different from an accountant?
Accountants focus on compliance and historical reporting. Fractional CFOs focus on strategy, forecasting, fundraising, and financial decision-making.
When should a startup hire a fractional CFO?
Typically during rapid growth, fundraising preparation, or when financial complexity exceeds the founder’s expertise.
How long do fractional CFO engagements last?
Engagements are often ongoing and adjust over time as company needs evolve.
Where can I find a qualified fractional CFO?
Size.vc connects founders and investors with vetted fractional CFOs who have scaled high-growth companies and understand the demands of venture-backed environments.