Here we have discussed how the actual CAC is calculated for startups. Considering all the marketing channels.

let’s say 10,00,000 users saw the ad, 10% of those users, i.e., 1,00,000 users clicked on the ad. A further 20% or 20,000 users checked out the product and registered on it. With an ad spend of ₹2,00,000, the product acquired 20,000 new customers.

So, CAC for Facebook ads = ₹2,00,000 / 20,000 = ₹10. 

Similarly, you can calculate the CAC for. Instagram & Google ads.

Blended CAC = total spend on user acquisition across channels/total users acquired from all the channels.