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🎯 CAC Calculator

Calculate your blended customer acquisition cost and compare it channel by channel.

Overall Spend & Customers
$
Channel Breakdown ?
Channel Spend Customers
CAC Payback Assumptions ?
$
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Ready to Calculate

Enter your numbers, then click Calculate to see results.

CAC Results
Blended CAC
—
per new customer
Total New Customers
—
acquired
CAC Payback Period
—
months
Total S&M Spend
—
this period
Per-Channel CAC Comparison
ChannelSpendCustomersCAC
Guide

About the CAC Calculator

The CAC (Customer Acquisition Cost) Calculator is a free tool that tells you how much it actually costs, on average, to win one new customer — and where that cost is coming from. Instead of guessing whether your marketing budget is working, you enter total sales and marketing spend alongside the number of new customers it produced, plus a per-channel breakdown, and the calculator does the rest. It's built for founders, growth marketers, and finance teams who need a fast, honest read on acquisition efficiency before the next budget cycle.

How It Works

The calculator divides your total sales and marketing spend by total new customers acquired to produce a single blended CAC figure. It then repeats that same division for each channel you enter — paid search, social ads, content/SEO, or any others — so you can see which channels are quietly overperforming or underperforming the blended average. Finally, using an optional average monthly revenue per customer and gross margin, it estimates your CAC payback period: how many months of gross profit from a typical customer it takes to earn back what you spent acquiring them.

Why It Matters

A single blended CAC number can hide a lot. A channel with a high CAC might still be worth scaling if it brings in higher-value customers, while a channel with a low CAC might be quietly acquiring customers who churn immediately. Comparing CAC channel by channel turns a vague "marketing is expensive" feeling into a concrete reallocation decision. Pairing CAC with payback period also tells you how much cash risk you're carrying — a 3-month payback is far less risky than a 14-month one, even at the same blended CAC.

Tips for Accurate Results

  • Use a consistent time window for spend and customers — comparing a month of spend against a quarter of new customers will distort your CAC.
  • Include the full cost of acquisition: ad spend, sales and marketing salaries, tools, and agency fees, not just media spend.
  • Channel-level figures don't need to sum exactly to your blended totals — they're for relative comparison between channels, not a strict reconciliation.
  • Re-run the calculation whenever gross margin or average revenue per customer shifts, since both directly move your CAC payback period.
Formula

How CAC is Calculated

CAC measures the average cost of turning spend into a new customer.

CAC Formula
CAC = Total Sales & Marketing Spend / Total New Customers Acquired
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Compare CAC, Not Just Spend

Two channels can spend the same amount and produce very different results. Always compare CAC per channel, not raw spend, to see where your budget is working hardest.

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Pair CAC With LTV

CAC alone tells you cost, not value. Always read it alongside customer lifetime value — a high CAC can still be profitable if LTV is high enough.

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Watch the Payback Period

A shorter CAC payback period means less cash tied up per customer and less risk if growth assumptions change. Aim to shorten it over time, not just lower CAC.

FAQ

Frequently Asked Questions

Common questions about CAC calculations

What is CAC (Customer Acquisition Cost)?
CAC is the average amount you spend on sales and marketing to acquire one new customer. Formula: CAC = Total Sales & Marketing Spend ÷ Total New Customers Acquired. It is one of the core unit-economics metrics used to judge whether growth spending is efficient.
What's a good CAC?
There is no universal good CAC — it depends entirely on your customer lifetime value (LTV) and margins. A common rule of thumb is an LTV:CAC ratio of at least 3:1, and a CAC payback period under 12 months for subscription businesses. A CAC that looks high in isolation can still be excellent if LTV is high enough.
How does CAC relate to LTV?
LTV (customer lifetime value) and CAC are usually read together as the LTV:CAC ratio. A ratio of 3 or higher generally signals healthy, sustainable growth; a ratio near or below 1 means you are spending almost as much (or more) to acquire a customer as that customer will ever be worth.
What counts as "sales & marketing spend" in the CAC formula?
Include ad spend, sales and marketing salaries and commissions, marketing software and tools, agency and freelancer fees, and content or creative production costs for the period measured. Exclude costs unrelated to acquisition, such as customer support, product development, or general overhead.
Why calculate CAC per channel instead of just blended?
Blended CAC averages every channel together and can hide which ones are actually efficient. Breaking spend and customers down per channel — paid search, social ads, content/SEO, and so on — shows you exactly where to shift budget for the lowest cost per new customer.
How is the CAC payback period calculated?
The calculator multiplies your average monthly revenue per customer by your gross margin percentage to get monthly gross profit per customer, then divides blended CAC by that figure. The result is how many months of gross profit from a typical customer it takes to recover what you spent acquiring them.
Can I add or edit the channels beyond the default three?
The calculator starts with three example channels — Paid Search, Social Ads, and Content/SEO — and you can rename any of them and change their spend and customer figures to match your own channels. It's built for a handful of channels at a time for side-by-side comparison.
Do the channel-level spend and customer numbers need to match the totals exactly?
No. Channel figures are for relative comparison between channels only — they don't need to sum to your blended total spend or customers. The per-channel CAC in the breakdown table is calculated independently for each row.
Why does gross margin affect the payback period?
Payback period is measured in gross profit, not raw revenue, since gross profit is what's actually available to offset your acquisition cost. A lower gross margin means less of each revenue dollar counts toward payback, so the same CAC takes longer to earn back.
What counts as a "new customer" for this calculator?
Any customer who wasn't previously paying and starts paying within the period you're measuring — a new signup, a new contract, or a first purchase, depending on your business model. Be consistent about the definition and time window you use across both the total and per-channel counts.
How often should I recalculate CAC?
Most businesses recalculate monthly or quarterly, matching whatever period they use for marketing budget reviews. Recalculating more often, such as weekly, can be noisy for smaller customer counts since a handful of deals can swing the average significantly.
Can I export my CAC results?
Yes. Click "Export Result" to download a plain-text summary of total spend, total new customers, blended CAC, and CAC payback period.

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