Free Customer Acquisition Cost (CAC) Calculator

Customer acquisition cost (CAC) is the total amount you spend on sales and marketing to acquire one new paying customer. The formula is simple: CAC = Total Sales and Marketing Spend / Number of New Customers Acquired. A SaaS company that spends $50,000 on marketing and sales in a month and acquires 100 new customers has a CAC of $500.

CAC is one of the most important financial metrics for SaaS businesses because it directly determines whether your growth model is profitable. If your CAC is higher than what customers are worth over their lifetime, you lose money on every customer you acquire — and scaling faster only accelerates the loss. Getting CAC under control is a prerequisite for sustainable growth.

Investors and operators use CAC alongside LTV (customer lifetime value) to assess business health. A company with a $500 CAC and a $2,500 LTV has a 5:1 LTV:CAC ratio, which signals a strong acquisition model. A company with a $500 CAC and a $600 LTV is burning money on customer acquisition, even if revenue looks healthy on the surface.

Enter your total sales and marketing spend for the period and the number of new customers acquired in that same period. The calculator outputs your CAC immediately. Optionally enter your average customer lifetime value (LTV) to see the LTV:CAC ratio and CAC payback period.

For the spend input, include everything that goes toward acquiring customers: paid ads, content production, SEO tools, sales team salaries and commissions, marketing agency retainers, conference sponsorships, and any software used primarily for acquisition. Teams that only count ad spend consistently undercount their true CAC by 30–60%.

Run the calculator separately for each channel to see which has the lowest CAC. A Facebook campaign might show a $200 CAC while a Google Ads campaign shows $450. Combined, those look like a $300 blended CAC — but the channel-level view tells you where to put the next dollar of budget.

The basic CAC formula divides total acquisition spend by new customers. What gets counted in "total spend" is where most teams get it wrong. There are two versions: blended CAC and paid CAC.

Blended CAC includes all marketing and sales costs — paid ads, organic content, SEO, sales salaries, and tools. This is the truest measure of acquisition efficiency. Paid CAC counts only direct advertising spend. Paid CAC is always lower than blended CAC and looks better in reports, but it hides the true cost of your acquisition model.

For LTV:CAC, use customer lifetime value calculated as average monthly revenue per customer multiplied by average customer lifespan in months. For a SaaS product at $50 per month with an average 24-month retention, LTV is $1,200. If CAC is $300, the LTV:CAC ratio is 4:1. The CAC payback period is CAC divided by monthly revenue per customer — in this case 300 ÷ 50 = 6 months to recover acquisition cost.

CAC varies enormously by industry, sales model, and ACV (annual contract value). A B2C SaaS product at $10 per month needs a very different CAC than a B2B SaaS product at $500 per month. The right benchmark is not an industry average — it is whatever makes your LTV:CAC ratio work.

For B2C SaaS with low monthly prices (under $30), CAC needs to stay below $100 to maintain a healthy LTV:CAC ratio. At $20 per month with 18-month average retention, LTV is $360. A $100 CAC gives a 3.6:1 ratio — acceptable. A $200 CAC produces a 1.8:1 ratio, which is unsustainable.

For B2B SaaS with higher ACV, CAC can be much higher. A product at $500 per month with 36-month retention has a $18,000 LTV. A $3,000 CAC gives a 6:1 ratio, which is excellent. Enterprise deals with a 12-month sales cycle and six-figure ACV can absorb CACs of $10,000 or more. What matters is always the ratio, not the raw number.

Product-led growth (PLG) companies that convert free users to paid tend to have lower CAC because the product itself does part of the acquisition work. Typical PLG CAC is 40–70% lower than sales-led CAC for equivalent ACV. If you have a free tier, calculate CAC separately for PLG conversions and sales-assisted conversions to see which motion is more efficient.

The fastest way to reduce CAC is to improve conversion rates, not reduce ad spend. If your landing page converts at 2% and you improve it to 4%, you effectively halve your CAC without changing your media budget. Conversion rate optimisation (CRO) has a direct 1:1 relationship with CAC — every percentage point improvement in conversion reduces CAC proportionally.

Referral programmes and word-of-mouth are the lowest-CAC acquisition channels because the acquisition cost is a fraction of what paid channels cost. A customer who refers three new customers lowers your blended CAC across all four customers. Building referral mechanics into your onboarding is often more cost-effective than any incremental budget increase in paid channels.

Retargeting campaigns consistently produce lower CAC than cold acquisition because the audience already knows your product. Separating retargeting spend from prospecting spend in your CAC calculation shows the true cost difference. Most SaaS teams find that retargeting CAC is 50–70% lower than cold prospecting CAC, which means shifting budget toward retargeting raises overall acquisition efficiency.