CAC Payback Period
Number of months required for the gross profit generated from a new customer's ARR to recover the fully-loaded S&M spend used to acquire them. The single most decision-useful efficiency metric at the board level — it directly connects acquisition cost, ACV, and gross margin into one "how long until we break even on this customer" answer. Per the SMSB standard, the calculation must use gross-margin-adjusted ARR in the denominator (not raw ARR) to be cross-company comparable. Common pitfall: using raw ARR understates payback by ~25–30 percentage points and breaks comparability with peer benchmarks. — Sales KPI anchored to SaaS Metrics Standards Board.
Rogue ID: sales.cac_payback_period
Type: Number (months)
Domain: Sales
Definition
Number of months required for the gross profit generated from a new customer's ARR to recover the fully-loaded S&M spend used to acquire them. The single most decision-useful efficiency metric at the board level — it directly connects acquisition cost, ACV, and gross margin into one "how long until we break even on this customer" answer. Per the SMSB standard, the calculation must use gross-margin-adjusted ARR in the denominator (not raw ARR) to be cross-company comparable. Common pitfall: using raw ARR understates payback by ~25–30 percentage points and breaks comparability with peer benchmarks.
Formula
CAC Payback (months) = CAC / (Monthly New ARR × Gross Margin %). Per SMSB §CAC Payback Period: numerator is fully-loaded CAC (same definition as the CAC line), denominator uses gross-margin-adjusted monthly new ARR so the metric is comparable across companies with different cost structures.Why it matters
The decision-relevant single number for "is the acquisition motion working" — sub-24 months signals capital-efficient growth; > 36 months means each dollar of S&M is locking up cash for too long to justify scaling spend.
How to interpret
Per the SaaS-investor convention reflected in KBCM/Sapphire SaaS Survey 2024 benchmarking: < 24 months gross-margin-adjusted payback is healthy; 24–36 months is acceptable for early-stage / up-market motions; > 36 months requires either an explicit path to compress (motion change) or a strategic rationale (e.g. multi-year deferred-revenue contracts with strong retention).
Related KPIs
sales.cacsales.new_cac_ratiosales.blended_cac_ratiosales.gross_marginsales.new_businesssales.arr
Source
SaaS Metrics Standards Board · section: CAC Payback Period — published 2023-01-01.
Why does this cite SaaS Metrics Standards Board? Read the ontology methodology for the published vs editorial tier system, attribution rules, and dispute process.
Metric definitions reference standards published by the SaaS Metrics Standards Board (saasmetricsboard.com). imboard is not affiliated with, endorsed by, or a member of SMSB.
Stage relevance
| Company stage | Priority |
|---|---|
| Series A | Core |
| Series B | Core |
| Series C+ | Core |
| Public | Core |
Suggested for stages: Series A, Series B, Series C+, Public.
Default owning functions
- Sales
- Finance
Machine-readable
- This KPI as JSON:
/api/ontology/sales/cac_payback_period.json - All Sales KPIs:
/api/ontology/sales.json - Full catalog:
/api/ontology/index.json
Customer Acquisition Cost
Fully-loaded sales-and-marketing (S&M) expense incurred to acquire one new customer during the period. Per the SMSB standard, the CAC numerator includes salaries + commissions + benefits + travel + marketing programs + tooling — i.e. all S&M costs, not just direct-attribution paid acquisition. The denominator is new logos, not deals. Common pitfall: omitting fully-loaded comp (especially BDR/SDR base salary and CS-team cost-of-sale where they participate in expansion) understates CAC and inflates every downstream efficiency metric. The board cares about CAC alongside CAC Payback and the CAC Ratio family — single-number CAC is a building block, not a verdict. — Sales KPI anchored to SaaS Metrics Standards Board.
CARR
Contracted Annual Recurring Revenue — recognized MRR × 12 plus the annualized value of contracts that are signed but not yet live (i.e. implementation, ramp, deferred-start). Per the SMSB standard, CARR sits between ARR (live only) and pipeline (unsigned) on the revenue-certainty spectrum: contractually committed but not yet delivered. Boards reading CARR > ARR gap can quantify the in-flight implementation backlog and the leading indicator of next-period ARR. Common pitfall: counting verbal commitments or LOIs as CARR — only signed contracts qualify under the SMSB definition. — Sales KPI anchored to SaaS Metrics Standards Board.