Ecommerce PPC Calculators

How to use the three together

1. 01Start with break-even ROAS. This is the floor. Any campaign below this is losing money on every order, regardless of what the dashboard says.
2. 02Then run POAS. This converts headline ROAS into profit per pound spent. It tells you whether your "good" campaigns are actually contributing margin, or just covering variable cost.
3. 03Finally, run CSS bidding headroom. If you spend on Google Shopping or Performance Max, bidding through a CSS partner puts your full bid into the auction on eligible inventory. The calculator shows the headroom that creates. It is illustrative arithmetic, not a forecast of realised savings.

All three run on the numbers you enter; none uses a benchmark dataset. Definitions for every metric used live in the PPC glossary.

Who these are built for

Founders, finance leads and in-house performance teams running £10k/month or more on Google Ads who suspect the dashboard ROAS is hiding the real story. None of them require account access, sign-up, or a sales call. Plug in numbers, get the answer.

If you want the same calculation done against your real account data - with COGS, returns and shipping reconciled to your P&L - that is what a profit audit covers.