How much can you afford to spend on a customer?

Most ROI targets get set from gut feel. This calculator works out a customer's real lifetime value against your cost to acquire them — and shows you the exact ROI where you tip from profit into loss.

Why LTV:CAC matters more than ROI on its own

A single order's ROI tells you almost nothing about whether a customer is actually worth acquiring. What matters is what they're worth over time — their lifetime value (LTV) — set against what it costs to get them in the door (CAC). If your CAC is higher than their LTV, every new customer loses you money, no matter how good the ROI on that first sale looks.

What "add-on value" means

Think of it as the Tesco Meal Deal effect — extra spend that only happens because you got them in the door in the first place. It might be an upsell in the same basket, a bigger order than they'd normally place, or a rough average of everything they buy beyond your repeat count. It's not a hypothetical extra order — it's the incremental profit that acquisition itself unlocks.