How this calculation works
The chosen gross margin removes product-level costs before campaign costs are subtracted. The separate revenue/media-spend ratio is not the same as this contribution-based ROI. Your attributed revenue is an input; the calculator does not establish causation or choose an attribution model.
Campaign ROI = (revenue × gross margin − total campaign cost) / total campaign costA worked example
100,000 revenue at 40% gross contribution gives 40,000. Subtracting 25,000 campaign cost leaves 15,000, a 60% contribution-based ROI.
Good to know
A transparent arithmetic model using your inputs. Example prices, rates and multiples are demonstrations, not benchmarks or offers. No tax, exchange-rate conversion, live account access or automatic attribution is supplied. Monetary display is rounded; calculations retain additional precision.
Reference: Google Ads: understanding ROI (opens in a new tab) ↗
A revenue multiple can hide an unprofitable campaign
Revenue divided by media spend says how much attributed revenue corresponds to each unit of media cost. It does not remove product costs or other campaign expenses. A large revenue multiple is therefore not automatically a large profit return.
This page first applies your gross contribution margin to attributed revenue. It then removes media and other campaign costs. The resulting contribution-based ROI uses total campaign cost as its denominator, which is stated explicitly.
Attribution is an input, not a result of the calculator
A sale recorded after an advertisement is not, by that timing alone, proof that the advertisement caused the sale. The revenue input should follow a defined reporting or experimental approach suitable for your question.
Avoid subtracting the same campaign expense twice. The gross contribution margin should already reflect product-level costs but should exclude the campaign costs entered separately below it. Review the model definition before comparing its ROI with another dashboard.
A few questions, answered
Is this the same denominator as every financial ROI measure?
No. ROI definitions vary by purpose. This calculator names its contribution numerator and campaign-cost denominator so comparisons can use matching definitions.
What if gross contribution is zero?
With positive campaign cost, this model shows a −100% contribution-based campaign ROI. Revenue alone does not change that when the entered margin is zero.