LTV Sensitivity Calculator
See how gross profit LTV changes as churn and gross margin vary (simple 3x3 sensitivity).
Quick LTV models are simple but sensitive. Small changes in churn or gross margin can dramatically change LTV because churn sits in the denominator.
This calculator generates a 3x3 LTV grid by varying churn and gross margin around your base assumptions.
Prefer an explanation- Read the guide.
LTV sensitivity: how churn and margin change LTVCohort analysis playbook: retention curves, LTV forecasting, and paybackUnit economics hub: CAC, LTV, payback, and runway (a practical stack)Gross margin improvements: how margin changes LTV, payback, and growth ability
$
%
Uses +/- step around margin base to create a 3x3 grid.
%
%
Uses +/- step around churn base to create a 3x3 grid.
%
Tip: you can type commas (e.g., 10,000).
Example
Using the default inputs, the result is:
$5,333.33
- ARPA (monthly)
- $200
- Gross margin (base)
- 80%
- Margin step
- 5%
- Monthly churn (base)
- 3%
- Churn step
- 1%
How to calculate
- Enter ARPA (monthly), gross margin, and monthly churn as base inputs.
- Choose step sizes for margin and churn (+/- around the base).
- Review the LTV grid and identify which lever matters most for your model.
Formula
Gross profit LTV ~= (ARPA x gross margin) / churn; Sensitivity varies gross margin and churn around a base case
- Uses a constant-churn shortcut model (planning).
- LTV is modeled as gross profit (ARPA x gross margin) to align with CAC and payback.
- Only shows a small grid; use cohort curves for precision.
FAQ
Why is LTV so sensitive to churn-
Because churn is in the denominator. Small changes in churn can create large changes in lifetime and therefore in LTV in simple models.
Should I use this instead of cohort LTV-
Use this for planning and sensitivity. For accuracy, use cohort-based LTV from observed retention and expansion over time.
Common mistakes
- Treating constant-churn LTV as precise (use cohorts for accuracy).
- Using revenue LTV when comparing to fully-loaded CAC (mismatch).
- Mixing monthly ARPA with annual churn (unit mismatch).
How to interpret
How to use LTV sensitivity
- If LTV is most sensitive to churn, prioritize retention and activation improvements.
- If LTV is most sensitive to margin, prioritize COGS and variable cost improvements.
- Pair with payback and CAC to ensure growth is cash-feasible.
Related calculators
SaaS Metrics
CAC Calculator
Calculate Customer Acquisition Cost (CAC) from total acquisition spend and new customers.
SaaS Metrics
Fully-loaded CAC Calculator
Calculate fully-loaded CAC by including paid spend plus sales & marketing costs (salaries, tools, and other acquisition costs).
SaaS Metrics
LTV Calculator
Estimate customer Lifetime Value (LTV) using ARPA, gross margin, and churn rate.
SaaS Metrics
LTV:CAC Calculator
Compute LTV:CAC ratio and CAC payback using ARPA, gross margin, churn, and CAC.
SaaS Metrics
CAC Payback Period Calculator
Estimate how many months it takes to recover CAC (months to recover CAC) using gross profit.
SaaS Metrics
CAC Payback Sensitivity Calculator
See how CAC payback months change as ARPA and gross margin vary (simple 3x3 sensitivity).
Quick checks
- Keep time units consistent (monthly vs annual) across inputs and outputs.
- Segment by cohort/channel/plan before trusting a blended average.
- Use the related guide to avoid common definition and denominator mismatches.