SaaS Growth Calculator.

Churn compounds. 5% monthly churn means each month you keep 95% of last month. Over 12 months, that’s 0.95^12 ≈ 54% retention without any new growth. Even with 6% monthly growth, the math gets ugly fast. Cutting churn from 5% to 3% can double your 12-month MRR vs. the 5% baseline.

It’s a planning tool, not an oracle. Real SaaS growth has seasonality, channel saturation, and cohort effects this model ignores. Use it to compare scenarios ("what if we cut churn 2 points?") not as a forecast you’d show a board.

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.