CAC Payback Calculator.
How many months of gross profit it takes to earn back what you spent acquiring a customer. The single number that tells you whether your unit economics work — before the cohort data comes in.
Fully-loaded: ad spend + sales + onboarding ÷ new customers won.
MRR per customer at acquisition. Annual plans: use ARR ÷ 12.
SaaS: 70–85%. Agency services: 40–60%. Subscription eCom: 30–50%.
Under 12 months is Bessemer's benchmark for top-quartile SaaS. Your acquisition engine is funding itself — push budget.
How to read your number
CAC Payback = CAC ÷ (ARPU × gross margin). That's how many months of gross profit per customer it takes to earn back what you spent acquiring them. Notice the gross margin — payback is measured in profit, not revenue. Skipping the margin term is the most common way founders report payback figures that look better than reality.
Bessemer's “State of the Cloud” benchmark is the one most VCs and operators quote: under 12 months is healthy, 12–24 months is workable depending on retention, over 24 months means your acquisition engine is starving you of cash. Top-quartile SaaS pays back CAC in 5–7 months.
The trap is using ARPU at acquisition without accounting for churn. If your average customer churns at month 14 and your payback is 18 months, you're losing money on every signup — the LTV never gets there. Pair this with the LTV:CAC Health Check to see both sides of the equation.
If your payback is too long, there are exactly three levers: lower CAC, raise ARPU, or improve gross margin. Most accounts we audit have headroom in all three — usually 30%+ on CAC alone from killing dead keywords, fixing Quality Score, and rebuilding landing pages that under-convert.
Want a deeper read of your account? Get our 47-point written audit, five business days, no sales call.
