Unit Economics

Payback Period

The time required to recover customer acquisition cost from the gross margin a customer generates.

Formula

Payback Period = Customer Acquisition Cost ÷ Monthly Gross Margin per Customer

Also: CAC ÷ (ARPU × Gross Margin %)

Shorter = more efficient

Definition

What is Payback Period?

Payback period measures how long it takes to recover the cost of acquiring a customer from the gross margin they generate. A 6-month payback means customers become profitable after 6 months of paying you.

Shorter payback periods improve cash efficiency and reduce risk from churn.

Why Payback Period Matters

Payback period determines how much working capital you need to fund growth. With 12-month payback, every dollar of CAC ties up capital for a year before returning. With 3-month payback, capital recycles four times as fast.

Long payback periods also increase churn risk. If customers churn before payback, you lose money on that acquisition.

Payback Period Benchmarks

12 months or less is generally good for SaaS. Under 6 months is excellent. Over 18 months is concerning unless retention is exceptionally strong. SMB typically has shorter payback than enterprise due to lower CAC.

Example

Marketing investment payback:

  • CAC: $500 per customer
  • Monthly gross margin per customer: $100

Payback Period = $500 ÷ $100 = 5 months

After 5 months, the customer has generated enough margin to cover acquisition cost. Beyond 5 months is profit.

Stop Flying Blind. Start Scaling Smart.

Get complete financial clarity in under 10 minutes. No more broken spreadsheets, no more QuickBooks chaos—just the insights you need to scale with confidence.