CAC Calculator
Calculate customer acquisition cost: total sales and marketing spend divided by new customers won in the same period.
One division, two decisions about what goes in it
The calculator divides your sales and marketing spend by the number of new customers won: CAC = spend ÷ new customers. With the defaults, $50,000 and 200 customers give a CAC of $250.
The arithmetic is trivial. The result depends entirely on two choices you make before typing: which costs count as spend, and which customers count as acquired by it. Change either and the same business can report very different CACs, so write down your definition and keep using it.
Blended, paid and fully loaded CAC
Three common variants, using one quarter of a hypothetical business: $18,000 on ads, $32,000 on sales and marketing salaries, tools and agency fees, 200 new customers in total, 120 of them from paid ads.
| Variant | Spend entered | Customers entered | CAC |
|---|---|---|---|
| Fully loaded, blended | $50,000 | 200 | $250 |
| Paid only | $18,000 | 120 | $150 |
| Ad spend over all customers | $18,000 | 200 | $90 |
The last row is the flattering mistake: it divides only ad spend by every customer, including the ones who arrived through word of mouth or search. Paid CAC is useful for judging a channel. Fully loaded blended CAC is the one to use when you ask whether the business can afford its growth, because salaries and tools can outweigh ad spend, as they do in this example.
Matching spend and customers in time
Customers rarely sign up in the same month the money was spent. A campaign run in March may produce most of its customers in April and May, especially with long sales cycles.
Take the $50,000 quarter above. If you count only the 160 customers who signed during the quarter, CAC is $312.50. If you count the 250 customers attributable to that quarter's spend, including those who signed the following month, it is $200. A common fix is to lag the customer count by your typical time from first contact to purchase, or to calculate CAC over a longer window so the timing evens out.
Turning CAC into a payback time
CAC on its own doesn't tell you whether it's affordable. Compare it with what a customer earns you:
CAC payback (months) = CAC ÷ monthly gross profit per customer
If a customer pays $50 a month at an 80% gross margin, they generate $40 a month, so a $250 CAC is recovered in 6.25 months. Until then, each new customer is a cash outflow. The faster you grow, the more cash that ties up, which is why CAC and runway are worth reading together.
You can also set CAC against lifetime value. Make sure both use the same cost and margin definitions before you compare them.
Frequently asked questions
What happens if I enter zero new customers?+
The calculator divides by at least one customer, so with zero it shows your whole spend as the CAC. Read that as no customers acquired rather than as a real cost per customer.
Should existing customers who upgrade count as new customers?+
Usually not. CAC measures the cost of winning customers you didn't have. Upgrades and renewals are better tracked separately, along with whatever you spend to drive them.
Do free trial sign-ups count as acquired customers?+
Only if you also count them as customers everywhere else. Most businesses count paying customers, so a trial user is acquired when they first pay. Counting trials makes CAC look lower than what you actually spend per paying customer.
Embed this tool on your website
Free to use on blogs, school sites and intranets. Paste this code into your page's HTML; please keep the credit line.
<iframe src="https://utilityapp.lat/embed/business/cac-calculator" title="CAC Calculator" width="100%" height="660" style="border:0;max-width:760px" loading="lazy"></iframe> <p style="font-size:13px"><a href="https://utilityapp.lat/business/cac-calculator">CAC Calculator</a> by UtilityApp</p>