You don’t pick a CFO model—you pick outcomes. This guide gives you reproducible math (scope, utilization, cost stack, scenarios, and break-even) so you can decide which option delivers more value in the next 6–12 months without jeopardizing cash.

Who this is for: Founder–CFO teams at ~$10M–$150M revenue deciding between fractional support and a first FTE.

KEY TAKEAWAYS

• Start with scope & utilization, not titles.
• Compare all-in cost per outcome(not per hour).
• Run Base / Downside / Upside for 6–12 months and apply a simple break-even

What the decision is (in plain English)

Best when (Fractional)

• Sub-$50–$150M or transformation windows (fundraise, lender package, pricing overhaul, system upgrade).
• You need senior judgment fast(8–20 hrs/week) with named deliverables.
• Interim coverage while hiring or leveling up the team.Best when (FTE)
• Scale stage with steady weekly leadership load: manage finance/RevOps, lenders, audits, board cadence, cross-functional planning.
• Persistent needs that reliably consume 40+ hrs/week.Criterion:Choose the model that hits your next three milestones fastest with the lowest cash risk. Quick test: List your next 3 milestones. If two or more are discrete projects (lender memo, forecast rebuild, pricing work), you’re likely fractional now, FTE later.

Scope & utilization (the inputs that matter)

Scope checklist

• Strategic finance & planning (model, scenarios, board package)
• FP&A cadence (weekly KPI, monthly refresh, quarterly re-baseline)
• Fundraising / banking (debt options, data room, covenant design)
• Controls & close (policies, audit readiness, RevRec)
• Systems (ERP/BI selection, implementation oversight)
• People leadership (hiring plan, coaching controller/analysts)

Utilization bands

• 8–10 hrs/wk= light guidance & project leadership
• ~20 hrs/wk= build/transform (model, debt process, pricing)
• 40+ hrs/wk= operate/scale (team mgmt, lenders, board cycle)Try this: Write your 3 milestones and put a monthly hour estimate next to each. That list is your utilization plan.

Cost stack (compare apples to apples)

Full-time CFO (FTE) all-in monthly
  = salary + benefits + payroll taxes + equity comp (amortized) + overhead

Fractional CFO monthly
  = rate × hours + travel/tools (if any) + optional on-site days

Formula: Cost-per-Outcome = All-in Monthly Cost ÷ Outcomes Delivered (milestones/month)

Illustrative ranges (your market will vary)

• FTE all-in:$28k–$45k / month (cash + benefits + taxes; equity amortized separately)
• Fractional:$250–$500 / hr; common packages $12k–$35k / month depending on scope & hours

Clarify upfront: Equity—show separately or amortize; be explicit. Benefits/taxes—use your actuals. Don’t compare list rates to fully loaded cash.

Quick test: If a model looks cheaper per hour but slower to milestones, your cost-per-outcome is likely worse.

ROI levers (what actually creates payoff)

•  Speed to milestone:exec pack live, lender term sheet, pricing changes shipped
• Cash impact:DSO/DPO improvements, opex reductions, vendor terms
• Risk reduction:covenant headroom, audit readiness, RevRec accuracy
• Leadership bandwidth:CEO/COO time reclaimed for GTM and productCue: If the model won’t move cash collected or decision speed inside 90 days, you’re buying optics—not outcomes.

6–12 month scenarios (Base / Downside / Upside)

All cases share the same timing and utilization framework; only the stated levers change.

 

Model	Monthly Cost	Milestones / Month	Cash Impact (Run-Rate)	Cost-per-Outcome	Notes
Fractional (Base)	$20,000	1.5	$40,000	$13,300	Forecast + lender pack
FTE (Base)	$35,000	2	$50,000	$17,500	Team mgmt + board cadence
Fractional (Down)	$20,000	1	$25,000	$20,000	Vendor delays
FTE (Down)	$35,000	1.5	$30,000	$23,300	Ramp + hiring drag
Fractional (Up)	$20,000	2	$60,000	$10,000	Pricing ships on time
FTE (Up)	$35,000	2.5	$70,000	$14,000	Faster lender + audit prep

 

Break-even & decision rule

Break-even (months) = (FTE monthly cost − Fractional monthly cost) ÷ (FTE incremental monthly value)

Worked example: If FTE costs $15k/month more than fractional, but drives $10k more monthly value (faster cash impact + more outcomes), break-even = 1.5 months. If your next critical milestone is 90 days away and liquidity is tight, you may still start fractional now and switch at break-even.

Decision rule: Choose the model that reaches Milestone 3 fastest without breaching your runway guardrail.

 Switch criteria (keep this visible)

• ARR/scale milestone hit (e.g., $30M ARR)
• Steady weekly leadership load ≥ 35–40 hrs
• ≥ 2 consecutive months where weekly leadership load ≥ 35 hrs
• Lender/board cadence intensifies (audit, debt package, fundraise)
• Team size requires day-to-day management

Governance & cadence (so the choice stays right)

Cadence

• Weekly KPI stand-up; monthly forecast refresh; quarterly re-baseline.Artifacts
• Scope doc, assumption log, change log, version rule (same system as the Rolling Forecasts post).
• Change log: date, owner, assumption, rationale.
• Versioning: monthly snapshots (e.g., CFO_Model_YYYY-MM.xlsx) for reproducibility.
• Reconciliation note (≤5 lines): what changed, why, and who approved.Contracting tips (fractional)
• Outcome-based SOW, named deliverables, knowledge transfer plan.Onboarding (FTE)
• 30-60-90 with a finance roadmap and explicit “first three wins.”Try this: Add a recurring 90-min Forecast Refreshto the calendar now. Treat it like a client meeting—no reschedules.

Mini case study (tight)

A SaaS firm at $22M ARR faced nine months of runway and a debt renewal. They chose fractional first (20 hrs/wk) to deliver a runway-accurate model, lender data room, and pricing refresh in 8 weeks. Results: DSO −7 days, vendor terms +15 days, pricing +3% → $120k/month cash uplift. At $30M ARR, with board cadence and audit ramping, they switched to an FTE CFO with a 30-60-90 plan. The choice changed when utilization and steady leadership load did.

Sensitivity: what moves ROI the most?

Show deltas using your worksheet; typical high-leverage levers:

• Milestones/month ±0.5 → large swing in cost-per-outcome
• DSO −5 days → faster cash realization
• Vendor terms +15 days on top 3 contracts
• Pricing +2–3% with no volume loss

Common mistakes (and quick fixes)

• Comparing hourly rates instead of cost-per-outcome → use the formula.
• Over-scoping day one → lock 3 milestones, defer the rest to Phase 2.
• Ignoring ramp → fractional can start next week; FTE hiring = 60–90 days.
• No exit/switch plan → set switch criteria(ARR, team size, lender cadence).