Customer Acquisition Efficiency Calculator

Customer acquisition efficiency shows how productively your spend converts into new customers, both as the number of customers you win per dollar invested and as the cost to acquire each one. This calculator takes your total acquisition spend for a period and the number of new customers you won in the same window, then returns customers per $1,000 of spend alongside your cost per customer, also known as CAC. It is a practical, plain language way to answer a question every founder and marketer asks, namely how much it really costs to bring in a customer and whether that cost is moving in the right direction. Marketing leads, finance teams and growth operators use it to compare channels, set budgets and decide where to scale. To use it, enter your total acquisition spend and the count of new customers gained. The customers per $1,000 figure makes it easy to compare campaigns of different sizes on a level footing, while the cost per customer puts the same data into a familiar CAC number you can weigh against the value each customer brings. A few habits keep it honest. Include the full cost of acquisition, media, salaries, commissions and tools, not just advertising spend, so the figure reflects reality. Count only genuinely new paying customers and keep the period for spend and customers aligned, remembering that some spend takes time to convert. Track the numbers by channel where you can, because a blended figure can hide one channel that is very efficient and another that is bleeding budget. Most importantly, read CAC next to customer lifetime value, since efficient acquisition only matters if each customer is worth more than it cost to win them.

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$1,250
Cost per customer (CAC)
Customers per $1,0000.80

CAC = acquisition spend / new customers. Customers per $1,000 = new customers / spend x 1000. Estimate only, not financial or tax advice.

How it works

Cost per customer divides your total acquisition spend by the number of new customers won. Customers per $1,000 divides the new customers by spend and multiplies by one thousand. The first tells you what each customer costs, the second how many you win per $1,000.

Worked example

With $60,000 of acquisition spend and 48 new customers, CAC is $60,000 divided by 48, which is $1,250. Customers per $1,000 is 48 divided by $60,000 times 1000, which is 0.80.

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Frequently asked questions

What is customers per $1,000?

It is the number of new customers you win for every $1,000 of acquisition spend. It lets you compare campaigns or channels of different sizes on the same footing. A higher number means more efficient acquisition.

How is cost per customer worked out?

It is your total acquisition spend divided by the number of new customers won, often called CAC. So $60,000 of spend winning 48 customers is a CAC of $1,250. Lower is better, as long as quality holds up.

What spend should I include?

Include the full cost of acquiring customers, advertising, salaries, commissions and tools, not just media. Leaving costs out makes acquisition look cheaper than it is. Be consistent every period.