CAC Calculator
Work out your customer acquisition cost in seconds. Enter what you spent on sales and marketing and how many customers it won you — get CAC plus an instant read on whether it's healthy.
Customer Acquisition Cost (CAC)
How much you spend, on average, to win one new customer.
Customer Lifetime Value (LTV)
The total gross profit you earn from an average customer before they churn.
LTV : CAC Ratio
The single most-watched SaaS efficiency number. 3:1 is the healthy benchmark.
MRR & ARR
Monthly and annual recurring revenue from your customer base.
Churn Rate
The percentage of customers you lose in a period — and the lifetime it implies.
Customer Retention Rate
The percentage of customers you kept, excluding new ones you added.
SaaS Valuation
A revenue-multiple estimate. Faster growth earns a higher multiple.
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What Is CAC (Customer Acquisition Cost)?
Customer acquisition cost is the total amount you spend to acquire a new customer. It is one of the most important metrics in any subscription or SaaS business, because it sets the price of growth: every dollar you pay to acquire customers has to come back — with margin to spare — over the life of the relationship. Track CAC and you know whether your acquisition efforts are 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. That single figure is what founders, operators, and investors use to judge marketing efficiency and decide how hard to push on spend.
How to Calculate Customer Acquisition Cost
The customer acquisition cost formula is one line: divide your 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 put into "spend" and in matching the spend to the customers it actually acquired in the same window.
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.
Why CAC Is Such a Vital Metric
CAC is the metric that tells you whether growth is sustainable. Spend more to acquire a new customer than they ever return and you are buying revenue at a loss — a hole that gets deeper the faster you scale. Keep CAC well below customer value and every acquisition compounds into profit. It is the single number that turns "we're growing" into "we're growing profitably," which is why it sits at the centre of every SaaS unit-economics conversation.
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 what a customer costs to acquire and their customer lifetime value (LTV, sometimes written CLV):
| LTV : CAC | Verdict | What it means |
|---|---|---|
| Below 1 : 1 | Losing money | You pay more to acquire a customer than they ever return. Fix before scaling. |
| 1 : 1 – 3 : 1 | Inefficient | Not yet ready to pour fuel on acquisition. Cut CAC or raise LTV first. |
| 3 : 1 – 5 : 1 | Healthy | The sweet spot — profitable and still investing in growth. |
| Above 5 : 1 | Under-investing | Great economics, but you could grow faster by spending more. |
Run your LTV against this CAC in the LTV calculator, then divide the two to find where you land. The full SaaS metrics hub ties CAC, LTV, churn, and MRR together in one place.
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. Optimise CPAs to improve efficiency at each step; report CAC when you want the honest cost of a customer for unit economics.
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.
Under 12 months is generally healthy for SMB SaaS; enterprise deals can justify longer. A short payback period means your growth is self-funding sooner and you can reinvest faster without raising money.
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 acquire customers far cheaper than paid ads over time.
- Tighten targeting. Spend that reaches qualified buyers converts better and wastes less.
- Shorten the sales cycle. Less time and touch per deal means lower fully-loaded cost per customer.
- Improve retention. Happy customers refer others — word of mouth is the cheapest acquisition there is.
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.
Frequently Asked Questions
What is a good CAC for SaaS?
There is no universal number — CAC only means something next to LTV. The rule that matters is the LTV : CAC ratio: your lifetime value should be at least 3× your CAC. A $500 CAC is excellent for a $10k-ACV enterprise product and terrible for a $10/month tool. Always judge CAC against what a customer is worth, not in isolation.
What costs should I include in CAC?
Everything you spent to acquire new customers in the period: paid ads and Google Ads, content and SEO costs, the fully-loaded salaries of sales and marketing staff, agency and tool costs, and sales commissions. Fully-loaded CAC (including people) is the honest number. Paid-only CAC understates your true cost of acquiring a customer.
Should CAC include salaries or just ad spend?
Include salaries. Ad-spend-only CAC flatters the number and hides your real cost of acquisition. Fully-loaded CAC adds the salaries of everyone in sales and marketing, plus commissions, tools, and agencies. It is the figure investors and disciplined founders trust because it reflects what winning a customer actually costs.
Does CAC include customer success or onboarding costs?
No. CAC covers only what you spend to acquire a customer, up to the point they become paying. Onboarding, customer success, and support are retention costs — they belong in your cost of serving customers (and therefore in gross margin and LTV), not in the acquisition number.
How does CAC differ from CPA?
CPA (cost per acquisition) usually means the cost of a single conversion event like a signup or lead. CAC is the cost of acquiring a paying customer. Several CPAs (lead → trial → paid) roll up into one CAC. For unit economics, CAC is the number investors and founders care about.
How does CAC relate to payback period?
CAC payback is how many months of a customer's gross-margin revenue it takes to earn CAC back. Payback = CAC ÷ (monthly ARPA × gross margin %). Under 12 months is healthy for SMB SaaS; enterprise can justify longer. A short payback means growth is largely self-funding.
How often should I measure CAC?
Monthly or quarterly, matched to your reporting cadence and sales cycle. Measure CAC over a period long enough to capture the full acquisition effort — short-cycle self-serve SaaS can look monthly; longer B2B pipelines are better read quarterly so spend and the customers it won line up.
How do I lower my CAC?
Two levers: pay less per customer or convert more of what you already pay for. Improve landing-page and trial-to-paid conversion rates, lean into lower-cost channels (SEO, referrals, community), tighten targeting so spend hits qualified buyers, and shorten the sales cycle. Retention helps indirectly — word of mouth from happy customers is the cheapest acquisition there is.
Is this CAC calculator really free?
Yes. No signup, no account, no limits. The calculation runs entirely in your browser and none of your numbers are stored or sent anywhere.