"APC" is a term you will commonly hear in the business. I don't know if APC stands for "Average Price per Customer" or simple "Average Per Customer", but the meaning is the same - how much revenues can you generate from each customer who walks into your restaurant. APC becomes critical while planning your restaurant and the space you would need and how you expect the customer flow to be at your restaurant.This is quite complex to explain in a single post as there are too many dynamic factors that determine APC, but I have made an attempt below.
In simple terms, if you expect to generate revenues of Rs. 15,000 per day and have a 50 seater restaurant, your APC will probably have to be Rs. 150 (let's assume 50 customers for lunch and dinner each). For a premium fine dining restaurant, the APC will be higher (Rs. 300 to Rs. 1000) and you can expect only one rotation of customers (i.e. each seat in the restaurant gets used only once during a lunch and dinner session). So if you plan to service 100 customers for lunch, you will need a 100 seater restaurant. For a budget restaurant, you can expect 2 rotations per session - i.e. each seat in the restaurant gets used by 2 different customers in each session. In Darshinis and Sagars, they end up doing 3 to 4 rotations. So a 20 seater Sagar restaurant will probably serve 80 customers during a lunch/dinner session.