The CAC Formulas
- Blended CAC = (sales cost + marketing cost) / new customers
- CAC payback (months) = CAC / (monthly revenue per customer × gross margin)
Use the same period for costs and customers. If your sales cycle is long, a quarter is a more stable window than a month, and some teams lag costs by one cycle so that spend is matched with the customers it produced.
Worked Example
Illustrative numbers: in a quarter, marketing costs 60,000 and sales 90,000. The team wins 25 new customers paying 1,200 a month at an 80% gross margin. Blended CAC is 6,000. Each customer produces 960 of gross profit a month, so payback is 6.25 months. If the same team improved demo-to-close from 20% to 25% without spending more, they would win about 31 customers and CAC would fall to roughly 4,800.
Where CAC Actually Comes Down
Most CAC conversations focus on cutting media cost. The bigger lever is usually conversion between steps: more of the right visitors becoming leads, more leads becoming opportunities. A website that shows a hospital buyer healthcare proof and a bank buyer banking proof converts more of the traffic you already paid for. See how industry-specific personalization works, and use the cost per lead calculator to see cost at each funnel step.
CAC also sits at the center of our list of B2B marketing KPIs, next to payback and pipeline-to-spend ratio.
Frequently Asked Questions
How do you calculate customer acquisition cost?
Add up sales and marketing costs for a period and divide by the number of new customers won in that period. 150,000 in combined cost and 25 new customers is a CAC of 6,000.
What costs should be included in CAC?
For blended CAC: media spend, marketing and sales salaries and commissions, agencies, events, and the software those teams use. Leave out costs that serve existing customers, such as customer success and account management, or report them separately.
What is CAC payback period?
The number of months of gross profit from a new customer it takes to earn back what it cost to acquire them: CAC divided by monthly revenue per customer times gross margin.
What is a good LTV to CAC ratio?
A ratio of around 3:1 is a widely used rule of thumb for SaaS, but it depends on how you estimate lifetime value, which is the shakier half of the ratio. Payback period is easier to measure and harder to fool yourself with.
Should CAC be calculated per channel?
Yes, once the blended number is stable. Channel CAC shows where to move budget, but it depends on attribution, so agree on the attribution rule before comparing channels.