A CAC calculator, or customer acquisition cost calculator, tells you what it really costs to win one new customer once every marketing and sales dollar is counted, not only the ad spend a platform reports. This one adds your marketing and sales costs, divides them by the new customers you won, and then compares the result with customer lifetime value and monthly gross profit, so you can see whether growth pays for itself and how long it takes to earn the money back.
How to Use the CAC Calculator
Pick one period, usually a month or a quarter, and enter every number for that same period. Everything runs in your browser and nothing you type is sent anywhere.
- Marketing spend ($): ad spend on every channel plus agency fees, freelancers, content production, marketing software and any promotions you paid for to win new customers.
- Sales costs, salaries and tools ($, optional): the share of sales and marketing salaries, commissions and tools such as a CRM that went into winning new customers. Leave it at zero for a paid media only view.
- New customers won: first-time customers in the period. Do not count repeat buyers, because they were already acquired.
- Customer lifetime value ($, optional): what an average customer is worth over the whole relationship. Use gross profit rather than revenue if you can, for the reasons explained below.
- Gross profit per customer per month ($, optional): the gross profit an average customer produces each month. For a subscription, it is the monthly fee multiplied by gross margin.
The calculator returns three results:
- Customer acquisition cost: total marketing and sales cost divided by new customers.
- LTV to CAC ratio: lifetime value divided by CAC, shown as a ratio such as 4.0 to 1. It appears only when you enter a lifetime value.
- CAC payback: CAC divided by monthly gross profit per customer, shown in months. It appears only when you enter monthly gross profit.
The note under the results flags the ratio. At 3 to 1 or above it reads as healthy. Below 3 to 1 it suggests lowering acquisition cost or raising customer value before you scale spend. The 3 to 1 line is a widely used rule of thumb, not a law, and the sections below explain when a different target makes sense.
The Customer Acquisition Cost Formula
You calculate CAC by dividing total sales and marketing costs for a period by the number of new customers won in that period.
CAC = (marketing spend + sales costs) / new customers
The two optional ratios use CAC as the denominator or numerator:
LTV to CAC ratio = customer lifetime value / CAC
CAC payback (months) = CAC / gross profit per customer per month
The formula is simple. The hard part is deciding which costs go in the top line and which customers count in the bottom line, and that is where most CAC numbers go wrong.
Worked CAC Example With LTV to CAC and Payback
Example numbers, not benchmarks. A subscription coffee brand spends $10,000 on marketing in a quarter, and $5,000 of a marketer's salary and CRM costs goes to acquisition. It wins 100 new subscribers.
- CAC = ($10,000 + $5,000) / 100 = $150
- Each subscriber produces $30 of gross profit a month and stays long enough to produce $600 of gross profit in total. LTV to CAC = $600 / $150 = 4.0 to 1
- CAC payback = $150 / $30 = 5.0 months
Now leave the salary and CRM line at zero and count marketing spend only: $10,000 / 100 = $100 CAC, a 6.0 to 1 ratio and a 3.3 month payback. Both views are correct. They answer different questions, and mixing them is the most common reason two people in the same company quote different CAC numbers.
What Costs Belong in CAC?
Include every cost that exists to win new customers and leave out the costs of serving customers you already have. The table is a practical starting point.
| Include | Usually exclude |
|---|---|
| Ad spend on all paid channels | Cost of goods sold and fulfillment |
| Agency, freelancer and creative production fees | Customer support for existing customers |
| Marketing and sales software used for acquisition | Retention email and loyalty program costs |
| Sales commissions on new deals | Account management for existing clients |
| The acquisition share of marketing and sales salaries | General overhead such as rent and finance |
| First-order discounts and sign-up incentives | Discounts given to repeat buyers |
Whether to include salaries depends on the decision. For pricing, fundraising or a board report, fully loaded CAC with salaries is the honest number. For deciding whether to add budget to one channel, paid CAC without salaries is fine, because the salaries do not change with the extra spend.
Blended CAC vs Paid CAC
Blended CAC divides all acquisition costs by all new customers, including customers who came from organic search, referrals and word of mouth. Paid CAC divides paid media costs by only the new customers that paid channels brought in.
| Version | Formula | Useful for |
|---|---|---|
| Blended CAC | All acquisition costs / all new customers | Overall business health and investor reporting |
| Paid CAC | Paid media costs / customers from paid media | Deciding whether to scale or cut ad spend |
| Channel CAC | One channel's costs / customers from that channel | Comparing Google Ads, Meta, SEO and referrals |
Blended CAC can hide a problem: strong organic sales make a loss-making paid channel look affordable. Paid CAC has the opposite risk, because it relies on platform attribution, which can over-credit ads. Track both and watch the gap between them.
CAC vs CPA: Why the Numbers Differ
CPA (cost per acquisition) measures the ad cost of one conversion on one platform, while CAC measures the full cost of winning one new customer across the business. A conversion can be a lead, a trial or a repeat purchase, so CPA is often lower than CAC.
A campaign can show a $40 CPA on leads while CAC is $400, because only one lead in ten becomes a customer and salaries sit on top. Use CPA to tune campaigns and CAC to decide how much the business can afford to grow. Our CPA calculator covers the campaign view.
What Is a Good CAC?
A good CAC is one that customers pay back within a period your cash flow can carry, and that sits well below what a customer is worth over their lifetime. There is no universal good CAC number, because a $300 CAC is cheap for a software subscription and ruinous for a single $40 order.
Judge CAC with two questions. First, how does it compare with lifetime value? That is the LTV to CAC ratio. Second, how fast does it come back? That is CAC payback. A business with plenty of cash can accept a longer payback to grow faster. A bootstrapped store usually cannot wait a year to recover what it spent on a customer. Ranges vary widely by industry, price point and sales model, so compare against your own history rather than a figure quoted for a different business.
Reading the LTV to CAC Ratio
The LTV to CAC ratio shows how many dollars of customer value you get for each dollar spent to acquire a customer. To use this page as an LTV CAC calculator, enter lifetime value and the ratio appears next to CAC.
- Below 1 to 1: every new customer loses money over their whole life. Scaling makes losses bigger.
- Around 1 to 1 to 3 to 1: acquisition is roughly covered, but there is little left for overhead and profit. The calculator flags anything under 3 to 1.
- 3 to 1 and above: the common target. Each customer returns several times their acquisition cost.
- Far above 3 to 1: healthy on paper, but it can mean you are underinvesting in growth and leaving customers to competitors.
One warning: the ratio is only as good as the LTV you enter. If LTV is revenue and CAC is cash spent, the ratio flatters you. Use gross profit LTV, which our customer lifetime value calculator gives you as a separate output.
CAC Payback Period and Cash Flow
CAC payback is the number of months a customer needs to generate enough gross profit to cover what it cost to win them. It matters more than the ratio when cash is tight, because a 5 to 1 ratio earned over five years does not pay this month's ad bill.
To use this page as a CAC payback calculator, enter gross profit per customer per month. For subscriptions, use monthly gross profit per subscriber. For ecommerce, where customers buy a few times a year, take the gross profit of a typical customer's first year and divide by 12 to get the monthly input. A payback longer than the average customer stays is a clear signal that the business cannot scale acquisition at the current CAC.
How to Lower Customer Acquisition Cost
You lower CAC by cutting the cost of each conversion, raising the share of conversions that become customers, or winning more customers from channels you already pay for. The practical levers:
- Cut wasted spend. Search term reviews, negative keywords, audience exclusions and placement checks remove clicks that never convert.
- Raise conversion rate. Faster landing pages, clearer offers and fewer checkout steps turn more of the same traffic into customers.
- Fix tracking. If platforms optimize toward duplicate or wrong conversions, bidding chases the wrong people. Clean conversion data often lowers CAC without any other change.
- Capture the people who did not buy. Email and SMS flows for sign-ups, browse abandonment and cart abandonment turn visitors you already paid for into first orders.
- Build channels without a click cost. SEO, referrals and content take longer but bring in customers whose acquisition cost falls over time.
Ecommerce CAC: Where to Find the Inputs
When you use this as an ecommerce CAC calculator, the new customers figure should come from your store, not from the ad platforms. Shopify's customer reports separate first-time and returning customers, and the same split is available in WooCommerce through order and customer exports. Ad spend comes from each platform's billing, and agency or app fees from your accounts.
Watch for two traps. Guest checkouts can create a second customer record for the same person, which inflates new customers. And a big sale can pull forward purchases from existing customers, so judge CAC on first-time buyers only.
If you came here for a coronary artery calcium (CAC) score, that is a medical test and this page is a marketing calculator, so speak to a doctor about those results.
When Your CAC Is Too High to Scale
If the calculator shows a ratio under 3 to 1 or a payback longer than you can fund, adding budget will make the problem bigger. The fix usually sits on both sides of the ratio: lower the cost of winning customers through better targeting, tracking and landing pages, and raise what each customer is worth through retention.
Our performance marketing work manages paid channels against CAC and payback targets rather than platform ROAS, and our email marketing and automation team builds the flows that turn first orders into repeat customers. If you want a second pair of eyes on your numbers, contact us with your current CAC and how you calculate it. More calculators are listed on our free marketing tools page.