The Five Finance Metrics Every Scaling-Up SaaS Founder Should Track (and Why We Obsess Over Them at OneProgram)

When we sit down with a prospective portfolio company, the first slide we pull up isn’t a glossy vision board—it’s a simple metrics dashboard. Numbers cut through narrative, and for B2B SaaS the “vital signs” are remarkably consistent across industries, whether you’re automating contract signatures (think SignIT) or streamlining media outreach (MyPressWire).

Below is the short-list we ask every founder to have ready before due diligence. Master these five metrics and you’ll speak the same language as your CFO, your board—and investors like us. (The framework is inspired by Ben Murray’s classic “Famous Five” metrics, but we’ve tweaked the commentary to fit the realities of European SaaS scale-ups.) (cobloom.com)

1. Monthly / Annual Recurring Revenue (MRR / ARR)

Why it matters: Recurring revenue is the heartbeat of any subscription model; it determines valuation multiples and capital-raise runway.

OneProgram lens: Break MRR down by product line and billing cadence. We routinely see founders blend yearly prepaid deals with monthly contracts—masking retention issues and skewing CAC payback. Separate streams, separate strategies.

2. Average Cost of Service (ACS)

What it is: The fully-loaded cost to keep an existing customer happy—hosting, support, success, account management, and the amortised slice of maintenance R&D.

Why we care: If your median deal size hovers perilously close to ACS (we’ve seen it!), you’re selling at a loss before CAC even enters the chat. For infra-heavy plays (e.g. AI model hosting at Sloif), shaving a few euros off cloud spend can flip contribution margin from red to black overnight.

3. Customer Acquisition Cost (CAC)

Make it actionable: Tag every sales & marketing euro directly to new-logo acquisition. No fuzzy “brand” buckets. Track by channel—paid search, outbound SDR, partner marketplace—and by segment (SMB vs mid-market).

Pro tip: In early-stage SaaS (sub-€1 m ARR) CAC is volatile. Normalise the input period to match your sales cycle; a 9-month enterprise motion requires 9 months of historical spend, not last quarter’s Adwords bill.

4. CAC Payback Period

Formula: CAC ÷ (MRR – ACS) → months to break even on a customer.

Our benchmark: < 18 months for SMB, < 24 months for mid-market. Anything longer means you’re financing growth with ever-larger funding rounds—expensive equity for founders and investors alike.

Reality check: Payback is where churn hides. If logo churn spikes, payback resets. That’s why we pair this metric with a three-year cohort table in every board deck.

5. Customer Lifetime Value (LTV)

How we calculate it:
((ARR – ACS) ÷ (Gross Churn % + WACC – Expansion Rate %))

Yes, it looks gnarly, but LTV tells a strategic story: the net cash a single customer produces, discounted for time value and attrition.

Rule of thumb: LTV should be ≥ 3× CAC. Below that line we dig into pricing, onboarding friction, or product-market mis-alignment before we talk about marketing budget.

Pulling It Together: The OneProgram Metric Stack

At OneProgram we don’t just invest capital—we plug founders into a shared tech and go-to-market engine. Every Monday our portfolio Slack channel lights up with an automated CSV containing:

1. ARR / MRR bridge (new, expansion, contraction, churn)
2. ACS trends vs hosting spend forecasts
3. CAC by channel with rolling six-month averages
4. Payback period heat-map across cohorts
5. LTV : CAC ratio drill-down by segment

If a number blinks red, we swarm. That “founder-plus-operator” mentality is why our companies hit milestones faster and keep more equity through to exit.