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CAC calculator.

Customer acquisition cost, plus the months-to-payback test investors actually care about. Tells you whether your blended CAC is cheap, healthy, or quietly killing you.

INPUTS
OPTIONAL — UNLOCKS PAYBACK MONTHS
RESULT
Customer acquisition cost
$1,500
CAC payback period
16.7 months
ACCEPTABLE

12-18 month payback is tolerable for enterprise SaaS but slow for SMB or PLG. Either expand ARPU, cut CAC, or shore up retention before raising spend.

FORMULA
01 / HOW IT WORKS

CAC is just spend divided by customers.

Customer acquisition cost is the total sales and marketing spend in a period divided by the number of new customers acquired in the same period. The hard part is being honest about what counts as spend.

CAC = (sales + marketing spend) / new customers

Include ad spend, agency fees, salaries of growth/sales people, tooling that exists to acquire customers, and any commissions. Skip product engineering and customer support — those are retention costs, not acquisition.

CAC payback adds ARPU and gross margin to estimate how many months of customer revenue you need to recover that spend.

CAC payback (months) = CAC / (ARPU × gross margin)
QUESTIONS
02 / FAQ

Quick answers.

What goes into 'sales + marketing spend'?+

All ad spend, marketing tooling, growth and sales salaries, agency fees, partner commissions, and event costs. Anything where the dollar exists to acquire a new customer. Skip product engineering, support, and infra — those are retention costs, not acquisition.

What's a good CAC?+

A good CAC is one you pay back in under 12 months at your gross margin. For SMB SaaS that often lands at $100-500. Mid-market $1,000-5,000. Enterprise $10,000-50,000+. The absolute number means nothing without LTV and payback context.

Should I use blended or paid CAC?+

Both, separately. Blended CAC (all spend / all new customers, including organic) tells you the truth about scaling cost. Paid CAC (paid spend / paid-channel customers only) tells you whether the channels you can throttle actually pay back.

What's the SaaS CAC payback benchmark?+

12 months is the long-standing target. 6 months or less is excellent. 18-24 months is acceptable for enterprise. Anything above 24 months is usually a sign of weak retention, weak pricing, or both.

How do I lower CAC?+

Three levers. First, conversion rate — the same traffic closing more customers cuts CAC linearly. Second, organic channels — content, SEO, Reddit, referrals don't show up in your paid CAC but lower blended CAC. Third, raise the price (smaller numerator effect, but it also boosts payback math).

Calculated your CAC? Now cut it.

The fastest way to drop CAC is more organic. Napkin runs UGC, Reddit, and GEO as one motion for AI companies. 15-minute call, no pitch deck.

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