Both options give you the same kind of person: someone who can build a model, talk to investors, and tell you when the plan doesn't add up. What changes is how much of that person you get, and how much of your cash and equity they take.
Founders often frame this as a budget question. It's more of a workload question. A brilliant CFO who is there one day a week can't help on the four days the problem shows up. A full-time CFO with nothing big to decide will spend expensive hours on work a bookkeeper should do. The sections below set out the published costs, a worked example, and the signals for switching.
What you get from a fractional CFO
A fractional CFO is an experienced finance leader who sells a slice of their week to several companies. Kruze Consulting, which sells the service, says a fixed monthly fee usually covers about one full day a week. Its list of what that day goes on is a useful scope checklist.
- Financial reporting and analysis for the founders and the board.
- Projections and budgeting, including the model investors will pick apart.
- Cash management, so you see the low point coming months ahead.
- Capital raising and negotiation, including terms on leases, insurance and other contracts.
- Running the finance systems and software.
- Turning the numbers into decisions, such as when to hire or how much to spend on marketing.
Quality varies a lot. Bridget Martinez puts it bluntly in a Pilot guide: "Some contractors generate spreadsheets. Others give you strategic insight you can act on." Pilot also sells fractional finance, so read both firms as interested parties. Before you sign, ask a candidate to walk you through one decision a past client made differently because of their work.
Fractional CFO vs full-time CFO: the published costs
No neutral survey of fractional CFO rates was available to read today, so the figures below come from firms that sell the service and from Payscale's self-reported salary data. Treat them as ranges to test against real quotes, as of November 2026.
| Cost item | Fractional CFO | Full-time CFO |
|---|---|---|
| Monthly or annual cost | $3,000 to $12,000 a month (Pilot); $8,000 to $16,000 a month (Kruze) | More than $250,000 a year (Pilot); $250,000 to $400,000 all-in at early stage (Kruze) |
| Hourly rate | $250 to $500 an hour, with $250 to $350 standard (Kruze) | Not billed by the hour |
| Annualized | $36,000 to $192,000 a year, from the monthly ranges above | As above, plus benefits and recruiting fees |
| Equity | Not part of the published fee ranges | 0.6% to 1.25% at early stage (Kruze) |
| Time on your company | About one day a week on a fixed fee (Kruze) | Every working day |
| Salary benchmark | Not applicable | $155,370 average base, $92k to $291k total pay (Payscale, all company types) |
Pilot's FAQ gives an average of $5,000 to $8,000 a month for early and mid-stage companies, and an example of about $3,000 a month for a pre-Series A startup that needs light strategic support. Kruze's numbers run higher because its fixed fee assumes a day a week. Kruze also notes a cheaper full-time step: a VP of Finance at $200,000 to $300,000 depending on experience. The Payscale figure covers CFOs at every kind of organization, so it's a weak guide to what a venture-backed startup will pay.
A worked example: a seed company with 18 months of cash
Take an invented company with $3.6 million in the bank after its seed round. It burns $200,000 a month, so it has 18 months of runway. It plans a Series A in about 12 months.
Fractional at $6,000 a month. That's $72,000 a year, or 3% of annual burn. Runway barely moves. The company gets a model, a monthly board pack and a fundraising partner one day a week.
Full-time at $300,000 all-in. That's $25,000 a month, or 12.5% of burn, plus up to 1.25% of the company. At this burn rate, that cash is about a month and a half of runway each year. In return, the company gets someone who is there when a customer asks for net-90 terms on a Tuesday.
For this company, fractional is the better deal for now. The month-and-a-half of runway matters more than daily access, because nothing in the business is complicated yet. Revisit the choice about a quarter before the Series A process starts. Kruze suggests considering a full-time hire at least that far ahead of a new raise. You can test your own numbers in the runway calculator.
Which model to use at each stage
- Pre-seed. Usually neither. You need clean books from a bookkeeper and an outside accountant, and the founder owns a simple model. See CFO vs controller vs bookkeeper for that first layer.
- Seed. Fractional, if anyone. The main jobs are a credible model for the next raise, a monthly report the board can trust, and cash planning. Pilot suggests a fractional CFO fits companies that have "outgrown bookkeeping-only support".
- Series A. Fractional, often with more hours. Some companies hire a VP of Finance here and keep a fractional CFO for the board and the raise.
- Series B and later. Full-time becomes the default. Kruze lists signals that the time has come: the CEO keeps getting pulled into reporting and projections, weekly accounting questions swamp the CEO, or an IPO is planned within 12 to 18 months.
Revenue and headcount thresholds in vendor guides vary widely, and none of the sources read for this page gives a firm one. Count the hours instead. If finance work that needs CFO-level judgment fills more than three days a week for several months, part-time no longer covers it.
Getting real value from a part-time CFO
- Write a monthly deliverables list. For example: board pack by the 10th, a cash forecast updated monthly, one pricing or hiring analysis a quarter. Hours without outputs drift.
- Keep the books with someone else. Your fractional CFO should review the close, not do it. At their hourly rate, reconciliations are the most expensive bookkeeping you'll ever buy.
- Give them direct access. Read access to the bank, the accounting system and the cap table saves a week of emails each quarter.
- Agree a response time. Decide what happens when a term sheet arrives on a day they're working for another client.
- Ask for a handover file from day one. The model, its assumptions and the board history should outlive the engagement, whether you later hire full-time or switch firms.
Signs you picked the wrong model
Fractional is no longer enough
- Decisions wait for the CFO's day of the week, and some of them can't.
- The CEO is building forecasts again because the CFO's hours ran out mid-month.
- Investors or the board ask questions between meetings that nobody inside can answer.
- You've added hours three times in a year and the bill is close to a salary.
Full-time came too early
- The CFO spends most days on bookkeeping cleanup or accounts payable.
- No raise, acquisition or major contract is planned in the next 18 months.
- The model gets rebuilt every month, but no decision changes because of it.
- The equity grant was large for a company this size, and the CFO is bored.
Whichever model you choose, the CFO works faster when the monthly numbers are already in one place. In Nautis, Startup Health records cash, MRR and burn in a monthly check-in, works out runway and flags trouble such as runway falling below six months. The Financial Planner builds a three- or five-year projection with P&L, balance sheet and cash flow, and its Shared Access setting lets a fractional CFO edit the same model or take it away as an Excel export. Nautis isn't an accounting system and doesn't replace the CFO's judgment. It gives them the numbers without a scramble.
FAQ
Is a fractional CFO worth it for a seed-stage startup?
Usually yes, if you're raising again within 18 months or your board wants proper reporting. Pilot's published range starts around $3,000 a month for light strategic support. If your books aren't clean yet, fix that first with a bookkeeper, or you'll pay CFO rates for cleanup.
How many hours does a fractional CFO work?
Kruze says a fixed monthly fee usually covers about one full day a week. Lighter engagements are a few hours a month around the board meeting. Agree the hours and the outputs in writing, since both drift.
When should a startup switch from a fractional CFO vs full-time CFO?
When CFO-level work fills most of every week, or a big event is coming. Kruze suggests hiring at least a quarter before a new fundraise, and flags an IPO within 12 to 18 months as a clear trigger. Many companies switch around Series B.
Can a fractional CFO run our fundraise?
They can prepare the model, the data room numbers and the answers to diligence questions, and many help negotiate terms. Kruze lists capital raising and negotiation among a fractional CFO's usual jobs. The CEO still leads the pitch and the investor relationships.