How to Calculate CAC (and Why Most Indian SMEs Get It Wrong)
A practical walkthrough of customer acquisition cost — what to include, what to leave out, and the mistakes that make CAC look better than it really is.
Customer Acquisition Cost (CAC) sounds simple: how much did it cost to get one paying customer. In practice, most small and mid-size businesses in India calculate it wrong — usually in a way that makes the number look better than reality.
The basic formula
CAC = Total sales & marketing spend ÷ Number of new customers acquired, in the same period.
The mistakes start with what goes into "total spend."
What people forget to include
- Agency or freelancer fees — not just ad spend, but who ran the campaign
- Tools — CRM, WhatsApp API, ad creative tools, landing page builders
- Sales team time — if a salesperson spends two hours per lead closing deals, that's a real cost
- Failed experiments — the campaign that didn't work is still part of what it cost to find the one that did
A common pattern: a business reports "₹200 CAC" using only Meta ad spend ÷ leads, when the fully-loaded number (including sales follow-up time and tools) is closer to ₹600–800.
Why this matters more than it seems
If your CAC is wrong, every other decision built on top of it is wrong too — how much you can afford to spend on ads, whether a channel is actually profitable, and how long a customer needs to stay before they're worth acquiring at all.
A better way to track it
- Pick a fixed period (monthly is usually enough for SMEs)
- List every cost tied to acquisition — not just media spend
- Divide by new customers only, not total customers
- Compare CAC against average order value or lifetime value, not in isolation
Run this exercise once a quarter and you'll usually find your real CAC is 2–3x higher than the ad-platform-reported number — which is exactly the number you need to make good decisions.