CAC Payback Period Calculator
Calculate your software company's CAC payback timeline and LTV:CAC efficiency ratio.
Typical B2B SaaS gross margins range from 75% to 85%.
Percentage of customers cancelling monthly.
What is the CAC Payback Period Calculator?
The CAC Payback Period Calculator is a financial analysis tool designed for SaaS founders, product marketers, and growth managers. CAC Payback measures the number of months a subscription customer must remain active before their gross profit margin fully offsets the initial Cost of Acquisition (CAC). This tool also calculates customer lifetime projections, Customer Lifetime Value (LTV), and evaluates your overall unit efficiency scorecard.
How Does the CAC Payback Period Calculator Work?
1. Enter Acquisition Cost (CAC) â Average dollar amount spent to acquire one new customer.
2. Provide Customer Pricing (ARPU) â The average monthly subscription rate.
3. Input Gross Margin (%) â The percentage of subscription revenue remaining after direct server/hosting costs.
4. Input Churn Rate (%) â Percentage of customers who cancel their subscriptions monthly.
5. Analyze Efficiency Ratings â Review payback months, LTV:CAC ratios, and overall health scores.
Formula & Calculation Method
SaaS Unit Economics Equations:
- Monthly Gross Profit: ARPU Ã (Gross Margin / 100)
- CAC Payback Period: CAC / Monthly Gross Profit
- Expected Customer Lifetime: 100 / Monthly Churn Rate (Months)
- Customer Lifetime Value (LTV): Lifetime (Months) Ã Monthly Gross Profit
- LTV:CAC Efficiency Ratio: LTV / CAC
Example Calculation
Example: Startup with $200 CAC, $30 ARPU, 80% Gross Margin, and 3% monthly churn.
- Monthly Gross Profit: $30 Ã 80% = $24.00
- CAC Payback Period: $200 CAC / $24.00 gross profit = 8.3 months
- Customer Lifetime: 100 / 3% = 33.3 months
- Lifetime Value (LTV): 33.3 months à $24.00 = $800.00
- LTV:CAC Ratio: $800 LTV / $200 CAC = 4.0x (Excellent efficiency, exceeding the 3.0x VC benchmark).
Frequently Asked Questions
**SaaS Unit Economics Equations:** - **Monthly Gross Profit:** ARPU Ã (Gross Margin / 100) - **CAC Payback Period:** CAC / Monthly Gross Profit - **Expected Customer Lifetime:** 100 / Monthly Churn Rate (Months) - **Customer Lifetime Value (LTV):** Lifetime (Months) Ã Monthly Gross Profit - **LTV:CAC Efficiency Ratio:** LTV / CAC
Disclaimer: This tool is provided for informational and calculation purposes. Output values are estimates based on standard user inputs.