CAC Calculator — Customer Acquisition Cost
Customer Acquisition Cost (CAC) tells you exactly how much it costs your business to win one new customer. It's one of the most important metrics for any business that spends money on marketing or sales — because if you're spending more to acquire a customer than that customer is worth over their lifetime, your business is structurally losing money with every new sale. This calculator makes it simple to measure and track your CAC over time.
What Is Customer Acquisition Cost (CAC)?
Customer Acquisition Cost is the total amount of money a business spends on sales and marketing to acquire one new paying customer. It is calculated over a specific time period — typically a month, quarter, or year — by dividing total sales and marketing expenditure by the number of new customers gained in that same period.
CAC is a fundamental metric for any business that actively spends money to attract customers. It tells you the efficiency of your customer acquisition efforts and, when compared to Customer Lifetime Value (LTV), tells you whether your business model is economically sustainable.
A business with a CAC of $200 and an LTV of $800 is in a healthy position — it spends $200 to acquire a customer worth $800. A business with a CAC of $200 and an LTV of $180 is losing money on every customer it acquires, regardless of how fast it grows.
How It Works
Choose a specific time period — a month, quarter, or year. Then enter:
- Total Sales & Marketing Spend: Every dollar spent on acquiring new customers during that period. This includes paid advertising (Google, Meta, LinkedIn, etc.), agency or freelancer fees, sales team salaries and commissions, marketing tools and software, events and trade shows, content production, and any other cost directly related to customer acquisition.
- New Customers Acquired: The number of new, first-time paying customers gained in the same period. Do not include repeat purchases from existing customers — those are retention, not acquisition.
The calculator divides total spend by new customers to give you your average CAC for that period.
Formula
Example Calculation
In Q1, a software company spent $18,000 on marketing: $10,000 on Google Ads, $5,000 on a content agency, $2,000 on a marketing tool stack, and $1,000 on a webinar. During the same quarter, they acquired 90 new paying customers.
CAC = $18,000 ÷ 90 = $200 per customer
If their average customer pays $80/month and stays for 18 months, their LTV is approximately $1,440 — giving an LTV:CAC ratio of 7.2:1. This is an excellent ratio.
When to Use This Calculator
- Monthly or quarterly tracking — calculate CAC regularly to spot trends. A rising CAC over time is a warning sign that your marketing is becoming less efficient.
- When evaluating a new marketing channel — run a campaign, then calculate the CAC for that specific channel to decide whether to scale it or cut it.
- When comparing CAC to LTV — use this alongside the LTV Calculator to assess whether your customer economics are healthy.
- When pitching to investors — investors in growth-stage businesses will almost always ask about CAC and LTV. Having accurate, up-to-date figures demonstrates financial discipline.
- When planning a marketing budget — if you know your target CAC and your growth target, you can work backwards to determine your required marketing budget.
Common Mistakes
- Including existing customer revenue in the "new customers" count. CAC measures the cost of acquiring new customers only. If you include repeat purchases or renewals, your CAC will appear artificially low.
- Forgetting to include sales team costs. Many businesses include ad spend but forget that their sales team's salaries, commissions, and tools are also part of the cost of acquiring customers. A complete CAC figure includes all sales and marketing costs.
- Measuring over too short a period. A single week or even a single month can be misleading due to timing differences between when you spend and when customers convert. Quarterly or annual CAC is often more reliable.
- Not segmenting by channel. Your blended CAC is useful, but knowing the CAC for each individual channel (paid search, organic, referral, events) is far more actionable. It tells you where to invest more and where to cut.
- Treating CAC in isolation. CAC only makes sense in the context of LTV. A CAC of $500 might be perfectly acceptable if your LTV is $5,000, but catastrophic if your LTV is $300.
How to Interpret Your Result
CAC alone is not enough to judge whether your business is healthy. The key metric is the LTV:CAC ratio:
- LTV:CAC below 1:1 — You are losing money on every customer. This is unsustainable.
- LTV:CAC of 1:1 to 2:1 — You are barely breaking even on customer acquisition. Very little room for error.
- LTV:CAC of 3:1 — Generally considered the minimum healthy ratio for a sustainable business. This is the benchmark most investors look for.
- LTV:CAC of 5:1 or higher — Strong. You may actually be underinvesting in growth — you could afford to spend more on acquisition.
Also track your CAC payback period — how many months of revenue from a customer it takes to recover the CAC. Use the Payback Period Calculator to calculate this.
Frequently Asked Questions
Should I include my own salary in the CAC calculation?
If you spend a significant portion of your time on sales and marketing activities, then yes — a portion of your salary should be included. The goal is to capture the true economic cost of acquiring customers. If you're a founder spending 50% of your time on sales, include 50% of your salary in the marketing spend figure.
How often should I calculate CAC?
Monthly tracking is ideal for fast-growing businesses. Quarterly is sufficient for more stable businesses. The important thing is consistency — calculate it the same way each time so you can track trends meaningfully. A rising CAC trend is an early warning sign worth investigating.
What is a good CAC for my business?
There is no universal "good" CAC — it depends entirely on your LTV. A $500 CAC is excellent if your LTV is $5,000 and problematic if your LTV is $600. Focus on the LTV:CAC ratio rather than the absolute CAC number. Use the LTV Calculator to calculate your LTV and compare.
How can I reduce my CAC?
Common strategies include: improving conversion rates on existing traffic (so you get more customers from the same spend), investing in organic channels like SEO and content marketing (which have lower marginal cost over time), building a referral programme (customers acquiring customers), and improving your sales process to close more leads. Reducing CAC is often more impactful than increasing revenue.
What is the difference between blended CAC and channel CAC?
Blended CAC is the average across all channels — what this calculator produces. Channel CAC is the cost of acquiring a customer through a specific channel (e.g., Google Ads only, or organic search only). Channel CAC is more actionable because it tells you which channels are efficient and which are not. Track both.
Disclaimer: This calculator provides estimates for informational purposes only. CAC calculations are based on the inputs you provide and represent averages over the chosen period. Actual customer economics will vary. Consult a qualified marketing or financial professional for comprehensive analysis.
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