Free Tool — CAC Calculator
Customer Acquisition Cost Calculator
Enter your marketing spend and new customers acquired to find your cost per customer.
Customer acquisition cost
₹500.00
Revenue-to-CAC ratio
1.6x
The number that tells you if marketing is working
Customer Acquisition Cost (CAC) is the average amount you spend to win one new customer, across all the marketing and sales costs that went into acquiring them. It only means something next to a second number — what that customer is actually worth to you.
Enter your total spend over a period and the number of new customers it brought in to get your CAC. If you also know the average revenue per customer, this calculator shows the ratio between the two — a quick gut-check on whether a campaign or channel is actually paying for itself.
Customer acquisition cost formula
CAC = Marketing & sales spend ÷ New customers acquired, for the same period. Revenue-to-CAC ratio = Average revenue per customer ÷ CAC. The ratio is shown only when you enter an average revenue figure; leave that field empty and it shows a dash.
How to use the CAC calculator
- 1Choose one period, such as a month, a quarter or the length of a single campaign, and use it for every figure.
- 2Enter Marketing & sales spend: the total you spent in that period to win new customers.
- 3Enter New customers acquired: first-time customers only, not repeat visits or returning patients.
- 4Optionally enter Average revenue per customer, ideally what a new customer spends with you over a fixed window such as their first six months.
- 5Read Customer acquisition cost and the Revenue-to-CAC ratio. A ratio below 1x means a typical customer brings in less revenue than it cost to win them.
- 6Repeat with the spend and new-customer count for each channel to see which one is cheapest.
Worked example: CAC for a clinic spending ₹30,000 a month
A physiotherapy clinic spends ₹20,000 on Google ads and ₹10,000 on a local newspaper insert in one month, and gets 80 new patients. Entered as one total, the CAC calculator gives ₹30,000 ÷ 80 = ₹375 per new patient. If a new patient spends ₹1,500 on average over a course of treatment, the revenue-to-CAC ratio is ₹1,500 ÷ ₹375 = 4x.
Run the channels separately and the picture changes. The ads brought 64 patients, a CAC of ₹312.50 and a ratio of 4.8x. The newspaper brought 16, a CAC of ₹625 and a ratio of 2.4x. The ratio uses revenue, not profit. If the clinic keeps 40% of revenue after consumables and therapist pay, the newspaper returns ₹0.96 of gross profit for every ₹1 spent (2.4 × 40%), so it does not quite pay for itself, while the ads return ₹1.92. Comparing CAC with customer lifetime value rather than one course of treatment makes this kind of call clearer.
Tips for an accurate CAC
- Count only first-time customers. Including repeat visits inflates the customer count and makes CAC look lower than it is.
- Allow for delay. Customers often arrive weeks after you pay for ads, so measure over a full month or quarter rather than a few days.
- Tag every new customer's source, by asking at billing or giving each channel its own coupon code, so you can calculate CAC per channel.
- Compare against gross profit, not just revenue. Multiply the revenue-to-CAC ratio by your gross margin to see how much gross profit each rupee of marketing returns.
- Do not judge a channel on first-bill revenue alone. A low ratio on the first visit can still work if those customers return regularly, so check their repeat rate before cutting it.
- Track CAC every month. A steady rise on the same channel can mean the audience has tired of the ad or offer, or that more competitors are targeting the same customers.
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CAC calculator FAQs
CAC = Total Marketing and Sales Spend ÷ Number of New Customers Acquired, over the same period. Spending ₹50,000 to acquire 100 new customers gives a CAC of ₹500.
Include ad spend, agency or platform fees, promotional discounts used purely for acquisition, and a reasonable share of sales team cost if relevant — anything spent specifically to bring in new customers during that period.
It depends entirely on what a customer is worth to you over time. A CAC is healthy if it's comfortably below the revenue (ideally repeat revenue) a typical customer generates — there's no fixed 'good' number across businesses.
CAC measures what you spent to win a customer; average order value measures what a customer spends per order once acquired. Comparing the two tells you roughly how many orders it takes to recover your acquisition cost.
It shows how many rupees of revenue a typical new customer brings in for every rupee spent acquiring them. The calculator divides your average revenue per customer by the CAC. A ratio of 4x means ₹4 of revenue for each ₹1 of acquisition cost, while anything below 1x means customers bring in less than they cost to win. Because it uses revenue, multiply by your gross margin before judging profitability.
ROAS, or return on ad spend, divides the revenue a campaign generated by what you spent on the ads, counting every sale it drove, including repeat buyers. CAC divides total acquisition spend by the number of new customers won. ROAS tells you whether a campaign paid back in sales; CAC tells you the price of each new customer, which you then compare with what that customer is worth over time.
Add up whatever you spent to attract first-time customers: referral rewards, free samples, printed flyers, a stall at a local event or a housing society notice-board campaign. Divide that by the new customers who came in during the same period. Word-of-mouth customers cost little to win, but tracking CAC still tells you whether a referral reward or sampling drive is worth continuing.
Customer lifetime value is the total profit a customer is expected to bring in over the whole time they buy from you, while CAC is the one-time cost of winning them. Comparing the two shows whether acquisition pays off in the long run. An LTV-to-CAC ratio of around 3:1 is a commonly quoted target, though what works for you depends on your margins and cash flow.
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