One acronym, four owners

CPA is a collision. A media buyer, an accounting student, someone reading a bank statement and someone navigating NHS care all type the same three letters and want four different pages. Most sites pick one audience and pretend the others do not exist. This one is built as a switchboard: it answers the advertising question first, because that is what most searchers mean, and routes the other three senses to real pages instead of dead ends.

Serving four audiences at once creates a sourcing problem the single-lane sites never face: an accountant fee survey and an ad-platform benchmark age on completely different clocks, so a bare figure tells you nothing about which lane it belongs to or how stale it is. Worse, the ad lane's biggest names publish nothing at all. Google, Meta and TikTok run auctions, not rate cards, and there is no official CPA benchmark for any of them. This site handles both problems the same way: pages that quote a figure stamp it with its publisher and survey year, and pages where no benchmark exists say exactly that, then show you how to compute your own. Both kinds of claim, the numbers and the absences, are on record in the Absence Register: every figure, its primary URL, its survey year, and the date it was pulled.

The calculators run entirely in your browser. No accounts, no stored inputs, no quote forms. If a number here disagrees with a fresher primary source, the primary source wins; the register row will say when we last looked.