SaaS Cash Flow Valley
See the payback valley and when cumulative cash crosses zero—single-customer cohort math, 100% local in your browser.
When to use this tool
- Pricing decisions where CAC payback is the gating metric.
- Board or investor conversations about cohort profitability.
- Comparing two pricing tiers side-by-side to see which hits cash-positive faster.
How it works
- Enter CAC (fully-loaded acquisition cost per customer).
- Enter monthly MRR per customer and gross margin.
- Enter monthly churn rate as a percentage.
- Read the cumulative cash curve and identify the month cash crosses zero.
Privacy: This tool runs entirely in your browser. Your input is not sent to our servers.
Model: one new customer, CAC paid immediately, then MRR each month while subscribers survive monthly churn c. Not a forecast for your whole business.
CAC payback period
23 months
LTV (simple: MRR ÷ churn)
$20,000
Red / green areas split at $0; cyan line is cumulative cash. LTV uses the textbook single-metric form MRR ÷ monthly churn.
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Frequently asked questions
Is this a full LTV/CAC model?
It is a single-cohort cumulative cash view — a truthful slice of LTV/CAC that highlights the payback valley without hiding churn.
What churn model is used?
Constant monthly churn applied against the current customer count. For more complex cohort churn, export to a spreadsheet.
How do I factor in expansion revenue?
Fold expansion into the MRR input by using the blended expected MRR per retained customer after month 6 or 12.