Marketing ROI Calculator — ROMI After Contribution Margin

Background.

A campaign report that says every advertising dollar brought back four has answered a revenue question. The finance team is asking something else: once the goods are paid for and the campaign is paid for, is the business better off? Return on marketing investment — ROMI, sometimes written MROI — is the measure built for that. The Marketing Accountability Standards Board's dictionary, drawing on Farris, Bendle, Pfeifer and Reibstein's Marketing Metrics, defines it as the contribution to profit attributable to marketing, net of marketing spending, divided by the marketing invested.

Three inputs go in, and each can distort the answer unnoticed. Incremental revenue means sales that would not have happened without the campaign — not everything sold while the ads ran. Contribution margin is the share of each sales dollar left after the variable cost of delivering it; it converts revenue into profit, and it is exactly the term that return on ad spend (ROAS) leaves out. Spend is everything the campaign put at risk: media, production, agency fees and any discounts it funded.

Because margin sits inside the formula, ROMI and ROAS can disagree about the same campaign. One identity makes the gap concrete: the ROAS a campaign needs just to break even is one divided by the contribution margin. A business earning 35% needs $2.86 of incremental revenue per dollar of spend to get its money back; one earning 22% needs $4.55. Thin-margin retailers can post a ROAS that looks excellent and still lose money on it.

The equation also runs backwards: give it a spend and a target return for the revenue a campaign must produce, or expected revenue and a target for the most you can afford to spend. One limit no rearrangement removes: response to marketing usually shows diminishing returns, so, as Dominique Hanssens writes for the American Marketing Association, ROMI depends on how much was spent, and campaigns of different sizes cannot be ranked by it.

What is marketing roi calculator?

ROMI is a percentage: incremental revenue multiplied by contribution margin, minus marketing spend, divided by marketing spend, times 100. Zero means the campaign exactly repaid itself; 100% means it returned its own cost again as profit; −50% means half the money was lost. It differs from ROAS, which MASB defines as sales attributable to ads divided by the cost of the ads — no margin, no subtraction — so a ROAS of 1.0 is a heavy loss while a ROMI of 0% is break-even. It is not a capital return either: MASB notes that marketing spending is normally expensed in the period and is risked rather than tied up in an asset, so there is no holding period to annualise. No accounting standard defines incremental revenue, which is why the figure can be no better than the test that measured it.

How to use this calculator.

1. 01Choose what to solve for: the return, for a campaign that has already run; or the revenue needed, or the maximum spend, when you are deciding whether to run one.
2. 02Enter incremental revenue from a holdout group, a regional test or a model with a proper baseline. If all you have is total sales during the campaign window, subtract what that period normally brings in first; otherwise the result is an upper limit, not an estimate.
3. 03Enter marketing spend, counting production, agency fees and the cost of any discounts or free shipping the campaign offered — not just the media invoice.
4. 04Enter contribution margin: price minus cost of goods, payment fees, shipping and any other cost that rises with each sale, as a share of price. Gross margin flatters the result slightly; net margin already deducts marketing and should not be used.
5. 05In the revenue and spend modes, set a target return (0% for break-even). Then compare your margin with the break-even margin output: if yours is the lower of the two, the campaign lost money at that revenue.

The formula.

With R for incremental revenue, S for spend and m for contribution margin as a fraction, ROMI = (R × m − S) ÷ S × 100. R × m is the gross profit the campaign produced, subtracting S leaves the net gain, and dividing by S expresses that gain per dollar risked. Setting ROMI equal to a target t (also a fraction) and rearranging gives the two planning modes: R = S × (1 + t) ÷ m and S = R × m ÷ (1 + t). At the default inputs — $40,000 of spend, a 35% margin and a 100% target — a campaign needs $228,571.43 of incremental revenue, and $250,000 of revenue at that margin and target supports at most $43,750 of spend. Setting ROMI to zero gives the break-even outputs: break-even revenue is S ÷ m, and break-even margin is S ÷ R, which is also one divided by the campaign's ROAS. ROMI is positive exactly when your margin beats the break-even margin. Each percentage point of margin moves ROMI by R ÷ S percentage points, so the higher a campaign's ROAS, the more sharply its return reacts to pricing and cost changes. Margin must be above 0% and no more than 100%, and a target of −100% or lower is rejected, because it would mean planning to lose the entire spend and the spend equation would divide by zero.

A worked example.

Frequently asked questions.

References& sources.

1. [1]MASB (Marketing Accountability Standards Board) — Universal Marketing Dictionary, entry "Marketing Return on Investment (MROI)". Verbatim: "Marketing Return on Investment (MROI) or Return on Marketing Investment (ROMI) is the contribution to profit attributable to marketing (net of marketing spending), divided by the marketing invested." Formula as published: "MROI (%) = 100 x [{Incremental revenue attributable to marketing ($) x Contribution margin (%) – Marketing spending ($)} ÷ Marketing spending ($)]". Also notes that marketing spending is typically expensed in the current period and that marketing funds are "risked" rather than tied up in assets. Free, independent, not paywalled. Retrieved 2026-07-29.
2. [2]Dominique M. Hanssens — "Using Return on Marketing Investment Effectively", American Marketing Association, published 24 July 2024. The second, independent authority used to check the definition above; it agrees on the arithmetic and adds the limits quoted on this page. Verbatim: ROMI is "net marketing contribution, found by multiplying revenue increase due to marketing by gross margin, subtracting marketing investment, and dividing the result by marketing investment"; "Consumer response to marketing activities is not linear. Research shows it is typically concave, with diminishing returns to scale, or S-shaped"; "ROMI depends critically on marketing spending" and therefore firms "cannot compare ROMI across different marketing campaigns or media, unless they spend the same amount on each"; marginal ROMI is "found by determining return on last dollar spent". Free, professional-body publication. Retrieved 2026-07-29.
3. [3]MASB — Universal Marketing Dictionary, entry "Return on Ad Spend (ROAS)". Verbatim: "Return on Ad Spend (ROAS) is a marketing metric that compares the sales generated by advertising to the corresponding advertising costs"; "Return on Ad Spend (%) = Sales Attributable to Ads ($) / Cost of Ads ($)". Cited on this page solely to establish that ROAS carries no contribution-margin term and no subtraction of spend, which is what separates it from the metric calculated here. Sourced by MASB from the Common Language in Marketing Project, 2022. Retrieved 2026-07-29.
4. [4]Farris, P. W., Bendle, N. T., Pfeifer, P. E. & Reibstein, D. J. — Marketing Metrics: The Definitive Guide to Measuring Marketing Performance, 2nd edition. Upper Saddle River, New Jersey: Pearson Education, 2010. This is the underlying source MASB cites for the MROI definition and formula used on this page. PRINT / BIBLIOGRAPHIC reference — there is no free public URL; the definition and formula were verified through MASB's dictionary entry rather than from the book directly.