TACoS Calculator
Plug in your pre-ads margin, target net margin, and revenue. Get your max TACoS, max ad spend, and max paid ACoS. Built from the same math I use to run accounts at $10M+ in annual ad spend.
Your numbers
Your limits
How this calculator works
The math is straightforward:
Max TACoS = CM1% − CM2% target- whatever margin sits between gross profit and your target net is the room you have for ads.Max monthly ad spend = Max TACoS × monthly gross revenue- convert the percentage into dollars.Max paid ACoS = Max TACoS ÷ ad-revenue share- the campaign-level ACoS ceiling depends on what share of your revenue actually comes from ads.TACoS floor = ceiling − 5 points- run 3 to 5 points below the ceiling so seasonality and competitor moves do not push you over.
These are upper bounds, not targets. If you can hit the same revenue at lower TACoS, take it. If your account sits 5+ points below the ceiling for two months, that is unused capacity, not victory.
What this calculator does not do: it does not account for organic cannibalisation, brand-term spending you might be paying for already, or one-off events like Lightning Deals. Use the output as a planning anchor, not a daily decision.
Want the diagnostic instead of the calculator?
If your TACoS is sitting above the ceiling and you can't figure out why, I run a 5-day account audit that diagnoses the actual cause and writes you a fix plan.
See the Account Audit service →