CAC Calculator (Customer Acquisition Cost)

What Is CAC (Customer Acquisition Cost)?

Customer acquisition cost is the total amount you spend to acquire one new paying customer. It is one of the core metrics in any subscription or SaaS business because it sets the price of growth: every dollar you spend to win a customer has to come back, with margin to spare, over the life of the relationship. Track CAC and you know whether your acquisition effort is building the business or quietly draining it.

CAC is a per-customer number. You take everything you spent chasing new customers in a period and divide it by how many you actually won. Founders, operators and investors use that figure to judge marketing efficiency and to decide how hard to push on spend.

How to Use This Customer Acquisition Cost Calculator

1. Pick one period. A month or a quarter, matched to your sales cycle.
2. Enter total sales and marketing spend for that period, fully loaded (see the list below).
3. Enter the number of new paying customers acquired in the same period.
4. Click Calculate CAC. You get cost per new customer and a short verdict on whether it looks low, typical or high.
5. Open the LTV : CAC tab and enter your lifetime value to see the ratio that actually decides whether the CAC is healthy.

Customer Acquisition Cost Formula

The CAC formula is one line: divide total sales and marketing spend by the number of new customers acquired in the same period.

If you spent $20,000 on sales and marketing last quarter and signed 40 new customers, your CAC is $500. The math is simple. The discipline is in what you count as spend and in matching that spend to the customers it acquired in the same window. People also search for this as a cost per customer acquisition calculator; it is the same calculation.

What to include in the spend figure

A CAC that only counts ad spend flatters you. The number founders and investors trust is fully loaded CAC, which includes every cost of sales and marketing:

• Paid advertising, Google Ads and sponsorships
• Content, SEO and creative production costs
• Fully loaded salaries of sales and marketing staff
• Marketing and sales tools (CRM, automation, analytics)
• Agency retainers and sales commissions

Leave onboarding, customer success and support out. Those are costs to serve and retain customers, not to acquire them. They belong in gross margin and in your lifetime value, not in CAC.

Blended vs paid CAC

Blended CAC divides all sales and marketing spend by all new customers, including those who arrived through organic search, referrals and word of mouth. Paid CAC divides paid-channel spend by the customers those channels produced. Blended CAC shows the overall cost of growth; paid CAC shows whether a specific channel pays for itself. Run the calculator twice with each set of numbers to see both.

LTV to CAC Ratio: What Counts as a Good CAC?

CAC is meaningless alone. A good CAC is any CAC comfortably below what a customer is worth. The benchmark is the ratio between customer lifetime value (LTV, sometimes written CLV) and CAC, which this page also calculates in its LTV : CAC tab:

Work out lifetime value in the LTV calculator, which uses revenue per account, gross margin and churn rate, then bring that number back to the LTV : CAC tab here.

CAC Payback Period

A second lens founders watch is CAC payback: how many months of a customer's gross-margin revenue it takes to earn back what you spent to acquire them.

With a $500 CAC, $50 in monthly revenue per account and an 80% gross margin, each customer contributes $40 a month, so payback takes 12.5 months. The shorter the payback, the sooner growth funds itself and the faster you can reinvest without raising money. Your monthly revenue per account comes straight from the MRR calculator.

CAC vs CPA: What's the Difference?

The two get mixed up constantly. CPA (cost per acquisition) is the cost of a single conversion event: a lead, a signup, a free-trial start. CAC is the cost of acquiring a paying customer. A funnel has several CPAs (cost per lead, cost per trial, cost per paid conversion) that roll up into one CAC. Optimize CPAs to improve each step; report CAC when you want the honest cost of a customer. To see how each funnel step converts, use the conversion rate calculator.

How to Lower Your CAC

There are only two levers: pay less to acquire each customer, or convert more of the traffic and pipeline you already pay for. In practice that means:

• Raise conversion rates. A better landing page or trial-to-paid flow lowers CAC without touching spend.
• Shift toward lower-cost channels. SEO, referrals and community tend to acquire customers more cheaply than paid ads over time.
• Tighten targeting. Spend that reaches qualified buyers converts better and wastes less. Check paid channels with the ROAS calculator.
• Shorten the sales cycle. Less time and touch per deal means a lower fully loaded cost per customer.
• Improve retention. Happy customers refer others, and referred customers cost little to acquire.

Built and tested by Alston Antony, who has reviewed 500+ SaaS tools and buys lifetime deals for a 15,000-member founder community. These calculators exist because founders shouldn't need a paid analytics seat to run napkin math on their own business.