A fractional CFO is an experienced chief financial officer who works with your company part-time, on a retainer or for a set number of days a month, giving you senior financial leadership without a full-time executive salary. Startups hire one when the finance work outgrows the founder and a bookkeeper but does not yet justify a full-time CFO, typically around a fundraise, a jump in complexity, or the first serious board reporting.
The demand is real and growing. Reporting from the sector suggests the number of practising fractional CFOs roughly doubled between 2022 and 2024, driven by the same efficient-growth pressure that made every founder runway-conscious (NOW CFO). This guide covers what the role actually delivers, what it costs, when you need one, and where software now covers part of the job.
What does a fractional CFO do?
A fractional CFO handles the strategic finance work above bookkeeping and accounting. Typical scope:
- Financial modelling and forecasting: the operating model, cash flow forecast and runway planning.
- Fundraising support: the model and data room for a raise, plus investor-facing narrative and diligence.
- Cash and burn management: watching burn, managing working capital, and flagging a crunch early.
- Board and investor reporting: the monthly and quarterly reporting pack.
- Unit economics and pricing: unit economics, margins and pricing strategy.
- Systems and hiring: setting up finance tooling and eventually hiring the in-house team.
The distinction that matters: a fractional CFO sells judgment, not data entry. They tell you what the numbers mean and what to do about them. That is why the role is different from an outsourced bookkeeper or accountant.
How much does a fractional CFO cost?
Pricing is usually a monthly retainer or an hourly rate. Commonly reported ranges:
| Model | Typical range | Notes |
|---|---|---|
| Hourly | ~$150 to $500/hr | Varies with experience and market |
| Monthly retainer | ~$3,000 to $10,000+/mo | Scales with days per month and scope |
| Annualised | ~$60,000 to $120,000/yr | Versus ~$250,000 to $450,000+ all-in for a full-time CFO |
Figures are commonly reported ranges (e.g. NOW CFO) and vary widely by market, seniority and scope; confirm with any specific provider. The core appeal is clear: senior financial leadership at a fraction of a full-time package, scaled to what you actually need.
When should a startup hire a fractional CFO?
It is a stage-and-complexity decision, not a revenue rule. The common triggers:
- You are raising. A credible model, data room and investor narrative is the single most common reason founders bring one in.
- Complexity jumped. Multiple revenue streams, international entities, or a move upmarket that your spreadsheet no longer handles.
- The board wants real reporting. Post-raise, investors expect a monthly pack the founder cannot keep producing by hand.
- The founder is the bottleneck. Finance work is eating the time you should spend on product and customers, but a full-time CFO is premature.
If none of these are true yet, you likely do not need one. Many pre-seed and seed founders run their own model, backed by a bookkeeper for the books, until one of the triggers above hits.
Fractional vs outsourced vs virtual vs full-time CFO
These terms get used interchangeably and cause real confusion. The practical differences:
| Fractional CFO | Outsourced CFO | Virtual CFO | Full-time CFO | |
|---|---|---|---|---|
| What it means | Senior CFO working part-time, often directly embedded | CFO delivered via a firm or agency | Fractional/outsourced CFO working remotely | Employed executive, full-time |
| Commitment | Days per month | Scoped engagement | Remote, flexible | Full-time |
| Cost | ~$60 to 120K/yr | Similar, firm-set | Similar | ~$250 to 450K+/yr |
| Best for | Startups needing senior finance part-time | Companies preferring a firm relationship | Distributed teams | Scale-ups with constant, complex finance needs |
In practice the labels overlap heavily. "Fractional" and "virtual" often describe the same person; "outsourced" usually implies you are hiring through a firm rather than an individual. Judge the engagement, not the word.
Do you need a fractional CFO, or software?
Here is the honest version most fractional-CFO marketing skips. A tool does not replace a CFO's judgment: negotiating a term sheet, deciding pricing strategy, or reading a board room are human jobs. But a large share of what a founder pays a fractional CFO for at early stage is modelling and forecasting work, and that part is now software.
If your need is mainly "I need a credible financial model, a rolling forecast, runway visibility and board-ready numbers", a modern SaaS-native planning tool covers it at a fraction of a retainer. If your need is strategic judgment and hands-on fundraising leadership, that is a human. Many founders use both: software for the model, a fractional CFO for a few days around a raise. This is complementary, not either-or, and the market data backs that: the tools and the people are growing together, not cannibalising each other.
The runway math below is the kind of number a fractional CFO would own, and that a tool can keep live for you automatically:
Frequently asked questions
What is a fractional CFO?
A senior chief financial officer who works with your company part-time, on a retainer or set days per month, providing strategic financial leadership (modelling, fundraising, cash management, board reporting) without a full-time salary.
How much does a fractional CFO cost?
Commonly around $150 to $500 an hour, or roughly $3,000 to $10,000+ a month on retainer, which annualises to about $60,000 to $120,000, versus $250,000 to $450,000+ all-in for a full-time CFO. Ranges vary by market and scope.
When should a startup hire a fractional CFO?
Usually around a fundraise, a jump in financial complexity, the point where the board expects real reporting, or when finance work is bottlenecking the founder, but the company is not yet ready for a full-time CFO.
What is the difference between a fractional CFO and an outsourced CFO?
Largely the delivery model. "Fractional" typically means an individual senior CFO embedded part-time; "outsourced" usually means the CFO comes through a firm or agency. The work is similar; judge the specific engagement.
Fractional CFO vs virtual CFO, what is the difference?
Little to none in practice. "Virtual" simply emphasises that the person works remotely. Both describe part-time senior finance help.
Can software replace a fractional CFO?
Not entirely. Software replaces the modelling, forecasting and reporting work, which is a big share of an early-stage engagement, but not the strategic judgment and hands-on fundraising leadership. Many founders use a tool for the model and a fractional CFO for a few days around key moments.
The software side of the job, in Adlega
Adlega is financial forecasting and planning built for SaaS, and it covers the modelling work a founder would otherwise pay a fractional CFO to do: a driver-based operating model, rolling 36-month forecast, MRR waterfall, burn and runway, scenarios for a raise, and board-ready output. Its AI CFO reviews your model, explains any calculation with full formula-level traceability, and answers finance questions conversationally, closing part of the gap that used to require a hire. It does not replace a human CFO's judgment, but it means you buy far fewer of their hours for the routine modelling. Try Adlega free while it is in beta.
Related reading: how to build a SaaS financial model, the SaaS fundraising guide, and cash flow forecasting software.