Signal Lab · Model
LTV:CAC & CAC Payback
LTV (lifetime value) vs CAC (customer acquisition cost) by channel — ratio and months to pay back. ACV (annual contract value) / ARPU (average revenue per user) is annual; churn is monthly. Distinct from Lead-to-Revenue and ARR waterfall — this is channel unit economics.
Illustrative AU SaaS / growth sample until you enter actuals. Not financial advice.
Channels, lifetime mode, and thresholds
Up to 4 channels. Persist locally · Jump to metrics
Blended and primary metrics
RAG vs your target LTV:CAC min and payback months max.
Equations
- CAC = Spend ÷ NewCustomers
- LTV (churn) = (ACV÷12) × (GM%÷100) ÷ (monthly churn%÷100) · ACV/ARPU annual · churn monthly
- LTV (lifetime months) = (ACV÷12) × GM% × LifetimeMonths
- Ratio = LTV ÷ CAC · Payback mo = CAC ÷ ((ACV÷12) × GM%)
- Blended CAC = Σspend÷Σcustomers; ACV, GM%, churn customer-weighted
How this is calculated
- CAC (customer acquisition cost) = Channel spend ÷ new customers acquired
- LTV (lifetime value) — churn mode uses monthly contribution ÷ monthly churn; lifetime mode multiplies monthly contribution by fixed months
- ACV (annual contract value) / ARPU (average revenue per user) entered as annual figures
- Payback months = CAC ÷ monthly gross-margin contribution
- Blended totals weight ACV, GM%, and churn by customers
Illustrative channel unit economics — not financial advice.
What-if dials
Monthly churn pts and spend % — live blended ratio and payback.
Churn & spend
Churn shock adds percentage points to every channel’s monthly churn. Spend shock scales every channel’s spend.
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Download a prompt, export the Excel workbook, or email yourself.
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