Free tools
Ecommerce calculators and KPI glossary
Four tools for the questions that matter when you pay for traffic: how much you can spend per order, what a customer really costs and whether the business as a whole is making money. Free, no sign-up.
Break-even ROAS
The lowest ROAS at which an order stops losing money, and the most you can pay in ads per order.
CAC from CPM
From CPM, CTR and conversion rate to cost per purchase, and what changes when you improve each one.
Break-even and target MER
The MER you need to break even this month and to hit your profit goal, fixed costs included.
Ecommerce KPIs
Every ecommerce metric with a definition, formula and worked example, from revenue to first-order profit.
How to use them
Which calculator to use first
- Start from marginThe break-even ROAS calculator tells you the most you can spend on ads per order.
- Check your campaignsThe CAC calculator shows what an order costs you today, from CPM, CTR and conversion rate.
- Look at the whole businessThe MER calculator adds fixed costs and total marketing spend to tell you if the month is profitable.
- Check the definitionsThe KPI glossary explains every metric with the same example store.
If the numbers don't add up and you can't see where margin leaks, that's what I work on as an ecommerce consultant and Meta Ads consultant.
Let's talk about your store
A 30-minute call to understand where you are, where you want to go and whether I can help. If I'm not the right fit, I'll tell you straight away.

