SaaS Churn Rate, LTV & Unit Economics Calculator – CAC Payback & Retention Model

Calculate SaaS Customer Lifetime Value (LTV), Monthly Logo Churn, LTV:CAC ratios, and CAC payback periods. Benchmark SaaS health against Bessemer Venture Partners standards.

Current Monthly Recurring Revenue ($)

Total Active Paying Customers (#)

Monthly Customer Logo Churn Rate (%)

Gross Margin Percentage (%)

Customer Acquisition Cost (CAC $)

Monthly Net Expansion / Upsell Rate (%)

Customer Lifetime Value (LTV)

$4,233

Gross-margin adjusted

LTV : CAC Ratio

3.02x

Benchmark: > 3.0x is elite

SaaS Unit Economics & Capital Efficiency:

Average Revenue Per User (ARPU):$144.44 / mo

Average Customer Lifetime:35.7 months

CAC Payback Period:11.8 months

Annualized Gross MRR Lost to Churn:$21,840/yr

Venture Capital Readiness Verdict:

Elite Unit Economics: LTV:CAC exceeds 3x with payback under 12 months. Safe to aggressively scale acquisition spend.

Net Revenue Retention (NRR): If expansion revenue from existing accounts exceeds the revenue lost from churned accounts, your business achieves Negative Net Churn (NRR > 100%), meaning your revenue grows each year even if you acquire zero new customers.

Venture capital and SaaS unit economics simulation for financial modeling only. Does not constitute formal securities legal counsel or valuation appraisal.

The Fundamental Unit Economics of SaaS: Churn, LTV & CAC

Software-as-a-Service (SaaS) businesses are valued on the predictability and durability of their recurring revenue. The relationship between Customer Churn, Customer Lifetime Value (LTV), and Customer Acquisition Cost (CAC) determines whether a company is an efficient compound growth engine or a cash incinerator.

The Core Formulas of Subscription Economics

Logo Churn vs Revenue Churn: Logo churn measures the percentage of customers who cancel each month. Net Revenue Churn factors in upsells and account expansions from surviving customers.
Average Customer Lifetime: Calculated as 1 / Monthly Churn Rate. A 2% monthly churn implies an average customer lifespan of 50 months.
Customer Lifetime Value (LTV): Calculated as ARPU × Gross Margin % / Churn Rate. Failing to adjust for gross margin inflates projected cash generation.
CAC Payback Period: The number of months required for a customer to pay back the sales and marketing dollars spent to acquire them (CAC / (ARPU × Gross Margin %)).

Bessemer Venture Partners SaaS Benchmarks

Top-quartile venture capital investors evaluate SaaS health using strict guardrails:

LTV:CAC Ratio > 3.0x: Every dollar spent on marketing yields at least $3 in gross profit over the customer lifecycle. Ratios below 2.0x signal unsustainable acquisition costs.
CAC Payback < 12 Months: Capital is recycled within one year, enabling rapid, non-dilutive organic reinvestment into growth.

Frequently asked questions

What is considered a good monthly churn rate in SaaS?

For enterprise B2B SaaS, monthly churn under 0.5% to 1% (approx 6-10% annually) is world-class. For SMB SaaS, 2% to 3% monthly churn is typical. Consumer B2C SaaS often experiences 4% to 7% monthly churn.

Why is gross margin critical when calculating LTV?

If a SaaS company earns $100/mo but spends $30/mo on cloud hosting, customer support, and payment fees (70% gross margin), using top-line revenue exaggerates true cash generation by over 40%.

How do annual contracts impact churn and cash flow?

Annual upfront contracts eliminate monthly cancellation risk, reduce involuntary churn from expired credit cards, and provide immediate working capital to finance customer acquisition.

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