Churn Impact Calculator

What is Churn Impact? Churn impact is the forecasted difference between a plan churn rate and a scenario churn rate on recurring revenue over time. It matters because churn is a...

Churn Impact Calculator

Model how a higher or lower churn scenario changes ending MRR, ARR run-rate, and cumulative revenue versus plan.

$

Current monthly recurring revenue at the start of the model.

$

Expected monthly new and expansion MRR before churn drag.

months

Number of months to model.

% / mo

Monthly churn rate in the plan case.

% / mo

Monthly churn rate in the scenario case.

Scenarios
Load common churn-scenario cases and see how the revenue gap compounds over time.
One point worseRetention improvementEnterprise churn pressure

Results

  • Ending MRR − plan$
  • Ending MRR − scenario$
  • MRR gap vs plan$
  • ARR run-rate gap$
  • ARR drag vs plan$
  • Cumulative revenue lost vs plan$
  • Extra net new MRR needed$
  • Scenario profile—

Enter your inputs above to calculate the results.

What is Churn Impact?

Churn impact is the forecasted difference between a plan churn rate and a scenario churn rate on recurring revenue over time.

It matters because churn is a growth tax: it reduces the compounding base of MRR, lowers the ending ARR run-rate, and forces higher net new MRR to hit the same plan.

In board/CFO terms, it shows the retention-driven drag on durable cash flows, efficiency metrics like SaaS Quick Ratio and Burn Multiple, and expansion health via Net Revenue Retention (NRR).

Formula

MRRplan0 = S,quad MRRscen0 = S
MRRplant = MRRplant-1(1-cplan) + g
MRRscent = MRRscent-1(1-cscen) + g
MRR Gap = MRRscenh-MRRplanh
ARRplanend = 12 × MRRplanh
ARRscenend = 12 × MRRscenh
ARR Gap = 12cdot(MRRscenh-MRRplanh)
Revenue Lost vs Plan = sumt = 1h(MRRplant-MRRscent)
greq = (MRRplanh-S(1-cscen)hright)cscen / 1-(1-cscen)h
Additional Net New MRR / Month = greq-g

Example

Assume: Starting MRR $250,000, Net new MRR/month (before churn) $20,000, Horizon 12 months, Plan churn 2% monthly, Scenario churn 3% monthly.

Month-by-month logic (conceptually): each month you add $20,000, then churn reduces the base more under 3% than 2%, so the gap widens over time.

Ending results (12 months):

  • Ending MRR (plan): $411,462
  • Ending MRR (scenario): $377,566
  • MRR gap vs plan: -$33,897
  • Ending ARR run rate (plan): $4,937,549
  • Ending ARR run rate (scenario): $4,530,788
  • ARR gap vs plan: -$406,761
  • Subscription revenue lost vs plan (over horizon): $196,015
  • Additional net new MRR/month to still hit plan ending MRR: $3,322

Frequently Asked Questions

How does the Churn Impact Calculator translate a churn increase (e.g., 2% → 3%) into an ARR shortfall?

It projects monthly MRR under your “plan churn” vs “scenario churn,” then annualizes the ending MRR (ARR run rate = ending MRR × 12) to show the ending ARR gap.

Does “Net new MRR per month (before churn)” include upgrades/expansion, or only new customers?

Treat it as your total net new MRR you expect to add each month before churn is applied to the existing base (new + expansion − contraction, if that’s how you track it).

Is churn applied once to the starting MRR, or does it compound monthly on the shrinking/growing base?

It compounds monthly: each month churn reduces the current MRR base, then your net new MRR is added for that month.

What does “Additional net new MRR/month to still hit plan ending MRR” actually mean?

It’s the extra monthly net new MRR you’d need (on top of your current net new MRR input) to overcome the higher churn and still land on the plan’s ending MRR by the end of the horizon.

Sources & Methodology