/ Calculator

What does a new customer cost you?

Spending a bag of money on ads is easy. Knowing whether it was worth it is hard. Three numbers you need for every channel: cost per customer, customer value, and how long until the money comes back.

Your numbers

Spent on the channel per month (€)Inquiries from the channel per monthHow many become customers (%)Average order (€)Gross margin (%)Orders per year from one customerYears a customer stays

Result

Cost per inquiry: €50
Cost per customer (CAC): €200
Customer value (LTV, profit): €640
LTV : CAC: 3.2 : 1
Payback: 7.5 months

Works. Above 3:1 the channel wins; above 5:1 you can probably invest more.

The formulas

CPL = spent ÷ inquiries
CAC = spent ÷ (inquiries × close rate)
LTV = order × margin × orders/yr × years
Payback = CAC ÷ (order × margin × orders/yr ÷ 12)

For comparison: an SEO customer costs $298–1,786, PPC $290–802, Facebook Ads $230 (First Page Sage, 3-yr average, US). 3:1 is a SaaS heuristic — for physical products ≥2:1 with a short payback is fine.