Customer Acquisition Cost Calculator
True CAC, payback months, and the LTV to CAC health check.
Customer acquisition cost
Estimates for planning only, not financial advice.
Customer acquisition cost is what you pay, all in, to win one new customer. Divide total sales and marketing spend by new customers won: $50,000 of spend for 400 customers is a $125 CAC. The number only means something against what the customer returns. At $150 a month in revenue, 75 percent gross margin, and a 24-month lifetime, each customer delivers $2,700 of lifetime gross profit, a 21.6 to 1 LTV-to-CAC ratio, which is outstanding. This calculator gives you CAC, the payback period, and that ratio in one pass.
How to Use This Calculator
Enter fully loaded sales and marketing spend for the period: ads, salaries, commissions, agencies, tools, and overhead share, not just media cost. Enter new customers won in the same period, counting only genuinely new logos, not renewals or expansions. Add average monthly revenue per customer, gross margin percent, and average customer lifetime in months for the LTV math. Use the same period definition every month so the trend is honest.
Total every sales and marketing dollar for the period, fully loaded with salaries and tools.
Count new customers only. Expansions and renewals belong to retention metrics, not CAC.
Read CAC, then the payback months and LTV to CAC ratio. If the ratio is under 3:1, fix acquisition or retention before scaling spend. Our customer lifetime value calculator builds the LTV side in more depth.
The CAC Formulas
CAC is a cost metric; LTV is a value metric; the ratio is the business judgment. A $125 CAC looks cheap until you learn the customer is worth $140, and looks expensive until you learn they are worth $2,700. The payback period adds the cash-flow lens: even a great ratio hurts if payback stretches past 18 to 24 months, because you fund every new customer out of pocket for two years before breaking even. Healthy SaaS targets 3:1 or better on the ratio with payback under 12 months.
Worked Example
A B2B SaaS company spends $50,000 in a quarter on sales and marketing, fully loaded, and wins 400 new customers: CAC is $125. Average revenue is $150 per customer per month at 75 percent gross margin, so monthly gross profit per customer is $112.50. Payback is $125 / $112.50 = 1.1 months, essentially immediate. With a 24-month average lifetime, LTV is $112.50 x 24 = $2,700, and the LTV to CAC ratio is 21.6 to 1. This company should spend more on acquisition, not less: every dollar of CAC returns nearly twenty-two. The constraint is finding more customers at similar quality, not the cost.
Reading Your LTV to CAC Ratio
| Ratio | Verdict | Move |
|---|---|---|
| Under 1:1 | Losing money per customer | Stop scaling, fix pricing or costs now |
| 1:1 to 3:1 | Thin | Improve retention or cut acquisition cost |
| 3:1 to 5:1 | Healthy | Scale efficiently, watch payback |
| Over 5:1 | Very efficient | Invest more in growth, test new channels |
Two warnings on the ratio. First, it collapses if churn rises, because LTV falls while CAC stays put; track both halves. Second, blended CAC hides channel truth: your best channel might run 8:1 while a new experiment runs 1:1, and the average says 4:1. Split CAC by channel monthly and reallocate from the losers to the winners. For channel-level math, our CPA calculator and CPC vs CPM comparison break down paid efficiency, and our churn rate calculator guards the retention side of the ratio.
Estimates for planning only, not financial advice.
Frequently Asked Questions
What is customer acquisition cost (CAC)?
CAC is the total cost of acquiring one new customer: all sales and marketing spend divided by the number of new customers won in the same period. Spend $50,000 on sales and marketing in a quarter and win 400 customers, and CAC is $125. It is the core efficiency metric for any growth engine: it tells you what each new customer actually costs to win.
What should be included in CAC?
All sales and marketing costs: ad spend, salaries and commissions for sales and marketing staff, agency and freelancer fees, marketing software, content production costs, and a fair share of overhead. The classic mistake is counting only ad spend, which understates CAC and flatters every channel. Fully loaded CAC is the honest number; paid-only CAC is a vanity metric.
How do you calculate CAC step by step?
Pick a period, usually a month or quarter. Add up every dollar of sales and marketing expense in that period, fully loaded. Count the new customers acquired in the same period, excluding renewals and expansions of existing accounts. Divide spend by new customers. Keep the period consistent month to month so the trend is comparable.
What is a good CAC?
There is no universal good number; it depends on what a customer is worth. The standard benchmark is the LTV to CAC ratio: lifetime value divided by acquisition cost. A 3:1 ratio or better is considered healthy for SaaS, meaning each customer returns three times what they cost. Below 1:1 you are destroying value with every sale; above 5:1 you are probably under-investing in growth.
What is the difference between CAC and CPA?
CPA (cost per acquisition) usually measures a single campaign or channel: ad spend divided by conversions from that campaign. CAC is the business-level number: all sales and marketing spend divided by all new customers. CPA tells you which ads work; CAC tells you whether the business model works. A campaign with great CPA can still sit inside a terrible CAC if sales headcount is bloated. See our CPA calculator for the campaign-level math.
Should CAC include salaries or just ad spend?
Include salaries. A CAC built only on ad spend answers "how efficient are our ads" while hiding the sales team that closes the deals. Both questions matter, so track both: paid CAC per channel for optimization, and fully loaded CAC for the business truth. When the two diverge sharply, the problem is in the sales process, not the ads.
How does CAC payback period work?
CAC payback is how many months of gross profit per customer it takes to recover the acquisition cost: CAC divided by monthly gross profit per customer. A $1,200 CAC against $100 of monthly gross profit per customer is a 12-month payback. Under 12 months is strong for SaaS; over 18 to 24 months strains cash flow even if the LTV to CAC ratio looks fine, because you fund the gap upfront.
Why is my CAC rising?
The usual causes: saturating your best channels, rising ad auction prices, expanding into less efficient segments, longer sales cycles needing more touches, or attribution leakage as privacy changes hide conversions. Diagnose by channel before cutting: a rising blended CAC with one broken channel is a reallocation problem, not a growth problem. Also check whether new-customer definition drifted; counting expansions as new customers masks the rise.
How can I lower CAC?
Improve conversion rates at each funnel stage (small lifts compound), shift budget to proven organic and referral channels, tighten targeting to your best-fit segments, shorten the sales cycle with better qualification, and raise prices or packaging so each won customer is worth more. Referral and word-of-mouth customers typically cost a fraction of paid ones, which is why product quality is ultimately a CAC strategy.
How does CAC relate to churn?
Churn attacks CAC from the value side. High churn shrinks lifetime value, which collapses the LTV to CAC ratio even if acquisition cost never moves. A business with $100 CAC and $300 LTV looks fine until churn doubles and LTV falls to $150. Track the ratio, not just CAC alone, because a "stable" CAC can hide a deteriorating business when retention slips.