CAC Payback Period Calculator Formula
Understand the math behind the cac payback period calculator. Each variable explained with a worked example.
Formulas Used
CAC Payback Period
payback_months = (monthly_revenue * gross_margin_pct / 100) > 0 ? cac / (monthly_revenue * gross_margin_pct / 100) : 0Monthly Gross Margin Per Customer
monthly_gm = monthly_revenue * gross_margin_pct / 100Variables
| Variable | Description | Default |
|---|---|---|
cac | Customer Acquisition Cost(USD) | 600 |
monthly_revenue | Monthly Revenue Per Customer(USD) | 100 |
gross_margin_pct | Gross Margin(%) | 75 |
How It Works
How to Calculate CAC Payback Period
Formula
Payback Period = CAC / (Monthly Revenue Per Customer x Gross Margin %)
The payback period tells you how quickly each new customer starts generating net profit after covering the cost of acquisition. Shorter payback periods mean faster cash recovery and less capital risk. Investors consider this alongside LTV:CAC because a great ratio with a 36-month payback still strains cash flow.
Worked Example
A company spends $600 to acquire a customer who pays $100/month with a 75% gross margin.
- 01Monthly Gross Margin = $100 x 75% = $75
- 02Payback Period = $600 / $75 = 8.0 months
- 03It takes 8 months to recoup the acquisition investment.
Frequently Asked Questions
What is a good CAC payback period?
Under 12 months is generally considered healthy for SaaS. Under 6 months is excellent. Enterprise SaaS with long sales cycles may accept 18-24 months if LTV is correspondingly high.
Why include gross margin in the calculation?
Not all revenue is profit. Some goes to hosting, support, and delivery costs. Using gross margin gives a realistic picture of how quickly you actually recoup the acquisition cost from real profit, not just revenue.
Learn More
Guide
How to Calculate Customer Lifetime Value
Learn how to calculate Customer Lifetime Value (CLV/LTV) using multiple methods. Understand why LTV matters for acquisition budgets, retention strategy, and business growth.
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Open CAC Payback Period Calculator