Marketing ROI Calculator
Incremental, and on contribution.
Marketing ROI
41.4%
328.6% if you use revenue and ignore baseline
Two corrections separate 328.6% from 41.4%: using contribution rather than revenue, and removing the sales that would have happened without any marketing. Both are usually omitted, and they compound.
How the Marketing ROI Calculator works
Two corrections separate a flattering marketing ROI from an honest one: using contribution rather than revenue, and removing the sales that would have happened without any marketing. Both are usually omitted, and they compound.
Not financial advice. Marketplace fees change, and they vary by country, plan and seller status. Every rate here is an editable default, not a quoted price — check the platform's current fee schedule before you price a product against it. This is not tax or business advice.
Frequently asked questions
How do I calculate marketing ROI?
Contribution from incremental revenue, less marketing spend, over marketing spend. Using revenue instead of contribution overstates it by the whole cost of goods.
What is baseline revenue?
The sales that would have occurred with no marketing at all — repeat customers, direct traffic, word of mouth. Attributing those to advertising is the largest single source of inflated marketing ROI.
How do I measure the baseline?
A holdout test: stop spending in a matched region and measure what still arrives. It is disruptive and it is the only method that answers the question directly.
What ROI should marketing deliver?
Enough to beat the alternative use of the money. For most ecommerce that means comfortably positive after contribution and baseline corrections, not the 5:1 revenue ratios usually quoted.