Real Growth Metrics
Economics Guide

CAC Payback Periods: What Your Investors Really Want to See

The one metric that determines whether your business can scale profitably. Learn how to calculate it, improve it, and communicate it to investors.

9 min readNovember 23, 2024

What is CAC Payback?

CAC Payback Period is the time it takes for a customer to generate enough profit to recover the cost of acquiring them. It's the most important economic metric for subscription businesses because it determines whether you can scale profitably.

The Simple Formula

Payback Period = CAC ÷ Monthly Gross Profit per Customer
CAC
Cost to acquire customer
Monthly Gross Profit
(ARPU × Gross Margin) - Costs
Result
Months to recover CAC

Why investors care: If it takes 12 months to recover your acquisition cost, you need customers to stay at least that long to be profitable. Shorter payback periods mean faster scaling and lower risk.

Calculate Your CAC Payback Period

Enter your business metrics below to calculate your CAC payback period. This is the calculation investors will do when evaluating your business.

Monthly Gross Profit per Customer

$35
(ARPU × Margin) after variable costs

CAC Payback Period

4.3 months
Time to recover acquisition cost
Healthy
Under 6 months
Caution
6-12 months
Problem
Over 12 months

Why Payback Period Matters to Investors

Investors evaluate businesses on three critical dimensions: growth, profitability, and risk. CAC payback period touches all three.

Growth

Short payback periods mean you can reinvest profits faster. Every dollar you spend on acquisition returns profit sooner, enabling compound growth.

Profitability

Long payback periods mean customers aren't profitable for a year or more. This creates cash flow problems and limits your ability to scale.

Risk

If payback takes 18 months but customers only stay 12 months on average, you're losing money on every acquisition. This is a high-risk business.

CAC Payback Benchmarks by Industry

SaaS Companies

Enterprise SaaS6-12 months
Mid-market SaaS3-6 months
SMB SaaS1-3 months

Other Subscription Models

Consumer Apps1-6 months
Media/Content3-9 months
E-commerce1-4 months

Note: These are general benchmarks. Your specific payback period depends on your pricing, margins, churn rate, and acquisition costs. Use our calculator to find your number.

How to Improve Your CAC Payback Period

1. Increase Gross Margins

Higher margins mean more profit per customer, shortening payback time.

Current Margin: 60%
Payback: 6 months
Improved Margin: 75%
Payback: 4.8 months
Target Margin: 80%
Payback: 4.2 months

2. Reduce Customer Acquisition Cost

More efficient acquisition directly improves payback period.

Current CAC: $200
Payback: 6.7 months
Improved CAC: $150
Payback: 5 months
Target CAC: $120
Payback: 4 months

3. Increase ARPU

Higher revenue per customer improves payback without affecting costs.

Current ARPU: $50
Payback: 6 months
10% increase: $55
Payback: 5.5 months
20% increase: $60
Payback: 5 months

Common CAC Payback Mistakes

Not Including All Acquisition Costs

Many businesses only count direct ad spend. Don't forget sales salaries, marketing tools, content creation, and overhead allocation.

Using Gross Revenue Instead of Profit

Payback should be calculated on profit, not revenue. A customer generating $100/month revenue but costing $80/month to serve has very different economics.

Ignoring Churn's Impact

High churn means customers don't stay long enough to pay back their acquisition cost. Always factor churn into your LTV calculations.

Not Monitoring Changes Over Time

CAC payback isn't static. As you scale, CAC typically increases while margins may change. Track this metric monthly and understand what drives changes.

Calculate Your CAC Payback Period

Use our CAC payback calculator to understand your customer economics and see how different factors affect your payback period.

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