Free CAC payback period, calculated instantly.
Calculate exactly how many months it takes to recover your customer acquisition costs. Enter your spend, new customers, ARPA, and gross margin below.
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Calculator Inputs
Results
Customer Acquisition Cost (CAC)
Payback Period
How to use this calculator.
CAC Payback Period is one of the most important metrics for a SaaS business. It tells you how capital-efficient your growth is. Here is what each input means:
Total Acquisition Spend
The total amount spent on sales and marketing. If you want to calculate this for a specific channel (recommended), use only the spend for that channel.
New Customers Acquired
The number of new paying customers acquired from that spend. Do not include trial signups or leads.
Monthly ARPA
Average Revenue Per Account. The average monthly revenue you get from these new customers.
Gross Margin (%)
The percentage of revenue left after subtracting the Cost of Goods Sold (hosting, support, etc). Usually 80-90% for SaaS.
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Divide CAC by the monthly gross profit per customer: CAC ÷ (monthly ARPA × gross margin %). For example, a $300 CAC with $150 ARPA at 80% margin ($120 gross profit) is a 2.5-month payback. Using gross profit rather than revenue keeps the number honest.
Most B2B SaaS targets under 12 months, with best-in-class under 6. Enterprise businesses with strong retention can tolerate 12–18. Anything beyond 18 months — especially early-stage — is a warning to examine channel mix and churn.
Total spend and count paying customers separately for each channel, then apply ARPA and margin per channel. Blended payback averages winners and losers together; per-channel measurement is the only way to know where to spend.
Yes. You recover acquisition cost out of gross profit, not revenue. Leaving margin out makes payback look faster than it really is — include it for an accurate, defensible number.
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