SaaS Simulator — MRR, Churn, Costs, Plans

Inputs

auto-saved

Simulation

Starting MRR ($/mo)

Current recurring revenue at Month 0.

Churn (% / month)

Applied to current MRR each month.

Growth model

Choose how you “add” revenue each month.

Net-new MRR ($/mo)

Example: +$1,500 MRR per month.

Expansion (% / month)

Example: +6% of current MRR per month.

Expansion start (% / month)

Early-stage growth (e.g. 15%/mo).

Expansion end (% / month)

Late-stage growth floor (e.g. 1%/mo).

Growth half-life (months)

How fast growth decays toward the end rate.

Early growth rate (% / month)

Approx % growth when MRR is tiny vs cap.

Market cap (max MRR)

As you approach this, growth asymptotically slows.

Target MRR ($/mo)

Used to answer “how long to reach X”.

Advanced

Months to simulate

Used for chart + summaries.

Plateau threshold (%)

For fixed net-new + churn > 0.

Plateau detection ($/mo)

“Plateau” when avg ΔMRR < this (over window).

Plateau window (months)

Trailing window for the average ΔMRR.

Costs & margins

Variable input costs (COGS %)

SMS, AI credits, infra, etc. (% of revenue).

Salary cost (% of revenue)

Owner pay + contractors as a % of revenue.

Fixed overhead ($/mo)

Tools, subscriptions, rent, etc.

Time horizon

Months to simulate

Used for chart + target solver.

Target MRR ($/mo)

Used for “solve demos needed”.

Funnel

Demos booked (per month)

Sent to plans by “demo share”.

Marketing spend ($/mo)

Used to compute CAC (spend / new customers).

Plans (3)

Plan A

Price ($/mo)

Demo share (%)

Close rate (%)

Churn (%/mo)

Starting customers

Plan B

Price ($/mo)

Demo share (%)

Close rate (%)

Churn (%/mo)

Starting customers

Plan C

Price ($/mo)

Demo share (%)

Close rate (%)

Churn (%/mo)

Starting customers

Costs & margins

Variable input costs (COGS %)

Used for gross margin + LTV calc.

Salary cost (% of revenue)

Fixed overhead ($/mo)

MRR results

monthly step model

Assumptions

Time step is monthly. Churn applies to existing MRR each month.

Fixed net-new model: MRR(t+1) = MRR(t)·(1 − churn) + netNew

Constant % model: MRR(t+1) = MRR(t)·(1 + expansion − churn)

Diminishing % model: expansion(t) = end + (start − end)·2^(−t/halfLife) → MRR(t+1) = MRR(t)·(1 + expansion(t) − churn)

Logistic model: MRR(t+1) = MRR(t)·(1 − churn) + r·MRR(t)·(1 − MRR(t)/cap)

“Profit” is monthly: revenue − COGS − salary% − overhead (no taxes, no balance sheet).

Plateau (detected) is a heuristic: average ΔMRR over a trailing window below a chosen $ threshold.

MRR results

Plans & funnel results