CAC Calculator

What is customer acquisition cost (CAC)?

Customer acquisition cost — CAC — is the average amount a business spends to win one new customer. You get it by adding up everything you spend on sales and marketing over a period, then dividing by the number of new customers that spend brought in. It's the headline unit-economics metric — the profit or loss on a single customer — the fastest way to check whether your growth is actually profitable, because a customer who costs more to acquire than they're ever worth is a loss, however fast you're growing.

Unlike a pure ad metric, CAC is a whole-business number — it counts far more than ad spend, which is exactly what makes it the figure investors and operators watch.

How to calculate CAC

To calculate customer acquisition cost, divide your total sales & marketing spend by the number of new customers acquired in the same period:

CAC = Sales & marketing spend ÷ New customers

For example, $45,000 of spend that brings in 300 customers gives a CAC of $150. Because the formula links three values, you can rearrange it to solve for whichever one you're missing — which is what the calculator above does:

• Find CAC — Spend ÷ Customers ($45,000 ÷ 300 = $150)
• Find Spend — CAC × Customers ($150 × 300 = $45,000)
• Find Customers — Spend ÷ CAC ($60,000 ÷ $200 = 300)

A worked example

A SaaS business spends $45,000 on sales and marketing in a quarter — ads, tools, agency fees and team salaries — and signs up 300 new customers. Its customer acquisition cost is:

$150 = $45,000 ÷ 300

Every new customer cost $150 to acquire. Working the other way: if the team lifted efficiency and cut CAC to $120, the same $45,000 would bring in 375 customers — the calculator shows exactly how much more growth a lower acquisition cost buys.

How to use this calculator

1. Choose which value to solve for — CAC, spend, or customers.
2. Enter the two values you already know. Results update instantly as you type.
3. Switch currency if you're planning in something other than dollars.
4. Use Copy shareable link to send the exact scenario to a colleague — the numbers are saved in the URL.

What's a good CAC?

There's no universal "good" CAC — a law firm can happily pay hundreds to win a client worth thousands, while a low-price app needs a CAC of a few dollars. What matters is that your CAC sits comfortably below your customer lifetime value; the LTV:CAC ratio (a ~3:1 rule of thumb) is the real test, not a benchmark chart.

Read the full guide: what is a good CAC? →

CAC vs CPA — not the same thing

CAC is often confused with CPA (cost per acquisition/action), but they measure different things:

• CPA is campaign-level — ad spend ÷ conversions, where a "conversion" is any tracked action (a lead, a signup, a sale). It tells you what a single action costs inside an ad platform.
• CAC is business-level — it counts every sales and marketing cost (salaries, tools, agencies, creative), not just ad spend, and divides by new paying customers.

Because CAC includes so much more than media cost, it's almost always higher than CPA. Use CPA to optimise individual campaigns, and CAC to judge whether the business as a whole acquires customers profitably.

How to reduce CAC

CAC falls when you win more customers from the same spend, or the same customers for less:

• Raise your conversion rate — a better landing page and offer turn more of the traffic you already pay for into customers.
• Tighten targeting and channel mix — shift budget to the channels that acquire your best customers cheapest, and cut the ones that don't.
• Lower your cost per click through ad relevance, so the same budget buys more qualified visits.
• Lean on retention and referrals — existing happy customers acquire new ones far more cheaply than paid channels.

CAC and your other metrics

CAC sits at the end of the funnel your ad metrics feed. Read it alongside them:

• CPC and CTR — the cost and efficiency of the clicks that start the journey to a customer.
• ROAS — the revenue side of the same campaigns; CAC is the cost side per customer.
• Campaign Forecast — model spend, conversions and cost per acquisition together before you commit a budget.