CAC Payback Period Calculator.

LTV:CAC is a long-run profitability metric: does the customer eventually pay back many times over? CAC payback is a cash-flow metric: how many months of payments before that customer is net cash positive? Both matter. Investors look at LTV:CAC; CFOs look at CAC payback.

Monthly margin (ARPU × gross margin per month). The result is in months. If you compute with annual margin, the result is in years × 12. Same number, different denominator. Stick with monthly to avoid confusion.

The formulas are textbook standard, used by ChartMogul, Baremetrics, OpenView, and most SaaS investors. Your numbers will be accurate to the inputs you provide. Garbage in, garbage out: pull the numbers from your billing system, not your gut.

MRR, ARR, ARPU: monthly. Churn, NRR: monthly with quarterly trend review. CAC, LTV, LTV:CAC, CAC payback: quarterly. They’re lagging and noisy on a monthly basis. Growth projection: refresh quarterly when you change your roadmap.

A 4% monthly churn rate is excellent for bootstrapped indie SaaS but alarming for enterprise SaaS. CAC payback of 18 months is dangerous for SMB but normal for enterprise. Stage-aware benchmarks tell you what good looks like at your size, not at someone else’s.

Yes, with adaptation. For usage-based pricing, normalise to monthly recurring billed amount before computing MRR. For hybrid (base + usage), include the recurring base in MRR and treat overage as expansion in NRR. The formulas don’t change. Only how you measure ARPU does.

Gross = before any offsetting moves. Net = after expansion or other positive flows offset losses. Gross churn ≤ net churn (net can be negative, meaning expansion outpaces loss). NRR includes expansion (net); GRR excludes it (gross). Both are reported in best SaaS dashboards.

No, never. Every metric here is paying-customers-only. Including trials inflates customer counts, deflates ARPU, and breaks comparability against industry benchmarks. Trials become "customers" the moment they convert to paid.

Investors care about: ARR (scale), MRR growth rate (momentum), monthly churn (retention), LTV:CAC (unit economics), and NRR if you have one. Seed: $0-100K ARR with strong growth. Series A: $1M+ ARR, sub-5% monthly churn, LTV:CAC 3x+. Series B: $5-15M ARR, NRR 110%+.

They’re a system. ARPU × customers = MRR. MRR × 12 = ARR. Customers × monthly churn = lost MRR. CAC + LTV + churn = unit economics. NRR + growth rate + churn = trajectory. Track them together. Improving one in isolation can mask trade-offs elsewhere.

Yes. Every tool on this page is free, no signup, no email gate, no upsell to a paid version. They’re built by FoundStep to help indie SaaS founders ship better businesses.

Benchmarks reference 2025-2026 data from ChartMogul Open Benchmarks, Baremetrics Open Benchmarks, OpenView SaaS Benchmarks 2024, and SaaS Capital’s annual report. Citations are linked under each benchmark table. We refresh annually.