ROAS Calculator

Background.

Return on ad spend is the simplest question in performance marketing: for every dollar of media, how many dollars came back? Divide attributed revenue by ad spend and you have it. This calculator runs that division in whichever direction you need — measuring a campaign that ran, working out the revenue a planned budget has to produce, or working out the budget a revenue target can support — and then does the thing most ROAS tools skip: it tells you what ROAS you actually need.

Start with the single most important warning, because it is the reason most ROAS numbers get misread. ROAS is revenue-based, not profit-based, and by itself it cannot tell you whether you made money. The MASB Universal Marketing Dictionary makes the distinction structural by carrying two separate entries: return on ad spend is sales attributable to ads divided by the cost of those ads, while return on investment is net profit divided by investment. Google Ads publishes the same split — its ROAS documentation divides sales by ad spend, while its ROI documentation states plainly that "ROI is the ratio of your net profit to your costs." A 5× ROAS is a comfortable win at a 60% gross margin and a straight loss at 15%, and nothing in the ratio itself distinguishes the two.

That is what the break-even ROAS output is for. It is the reciprocal of your gross margin: at 45% margin every revenue dollar carries 45 cents of gross profit, so you need 1 ÷ 0.45 = 2.22 dollars of revenue per media dollar just to stand still. Anything above that adds gross profit; anything below burns it. Enter your margin once and the ratio stops being a vanity number and becomes a decision.

Read the break-even figure as gross, though. It covers cost of goods and nothing else. Fulfilment, payment processing, returns, customer support, agency retainers and overhead all sit underneath it, which means the ROAS your business genuinely requires is higher than the threshold shown — often substantially so for physical products. The output panel says this beside the number rather than hiding it in a footnote.

The second caveat belongs here rather than in an accordion too: the numerator is entirely a product of your attribution model. The MASB dictionary's own entry flags that ROAS calculations in the early 2020s "often included non-advertising-driven sales, inflating results," and notes that when calculated correctly ROAS and incremental ROAS are the same metric. If your platform claims a sale that would have happened anyway, your ROAS is overstated and no amount of arithmetic here will catch it. Widening an attribution window raises reported ROAS without changing a single thing about the business.

Here is the worked example the page ships, computed by the same code that runs the widget. A campaign spent $12,000 and the attribution model credits it with $60,000 of revenue, so ROAS is 5.00× — or 500%, which is the same number in the notation Google Ads uses for a target. At a 45% gross margin the break-even ROAS is 2.22×, so 5.00× is comfortably profitable: $60,000 of revenue carries $27,000 of gross profit, less $12,000 of media leaves $15,000 of gross profit after ad spend. The break-even revenue on that spend is $26,666.67.

Now watch the two metrics diverge on those exact figures. Return on ad spend is 500%. Return on investment in that ad spend is $15,000 ÷ $12,000 = 125%. Same campaign, both correct, and a factor of four apart. Google's own ROI documentation produces the same effect on its own example — a campaign it works through as 50% ROI is a 600% ROAS. If you quote one number to a finance team expecting the other, the conversation will go badly.

One last note on rendering, because the sources genuinely disagree. Google Ads writes ROAS as a percentage: "$5 USD in sales ÷ $1 USD in ad spend x 100% = 500% target ROAS." Google Analytics writes it as a bare ratio. Amazon Ads writes it as odds — "a 2:1 ROAS ratio." And the MASB dictionary labels its formula "Return on Ad Spend (%)" while writing an expression that produces a ratio, which is an inconsistency in the source rather than a real disagreement. This page returns both renderings side by side so you can use whichever your platform speaks.

What is roas calculator?

Return on ad spend (ROAS) is the ratio of revenue attributable to advertising to the cost of that advertising. The MASB Universal Marketing Dictionary defines it as "a marketing metric that compares the sales generated by advertising to the corresponding advertising costs," used "to compare the performance of ads, media channels, platforms, etc.", and gives the formula as sales attributable to ads divided by the cost of ads. Google Ads expresses the same quantity as a percentage in its target ROAS documentation — "$5 USD in sales ÷ $1 USD in ad spend x 100% = 500% target ROAS" — while Google Analytics states it as a bare ratio of ecommerce revenue plus total goal value over advertising cost, and Amazon Ads describes it as "the amount of revenue from an ad campaign, divided by the amount spent on the campaign itself." All four are the same arithmetic. What distinguishes ROAS from return on investment is the numerator: ROAS uses revenue, ROI uses net profit. The same dictionary defines return on investment as net profit divided by investment times 100, citing Farris, Bendle, Pfeifer and Reibstein's Marketing Metrics — so a campaign can post a spectacular ROAS and a negative ROI whenever gross margin is thin. Break-even ROAS closes that gap: it is the reciprocal of gross margin, the revenue multiple required for the advertising to cover the cost of the goods it sold plus its own media cost. ROAS is also notably absent from ad-serving glossaries such as Microsoft's Xandr reference, which carries CPM, CPC, CPA and their effective variants but no ROAS entry — because ROAS is an advertiser-side outcome measure rather than a media pricing model.

How to use this calculator.

1. 01Choose what to solve for. Leave it on ROAS to measure a campaign that already ran. Switch to Revenue when you have a budget and a target ratio and want to know what revenue that implies. Switch to Ad spend when you have a revenue target and a ratio you can sustain, and want the budget it allows.
2. 02Enter the attributed revenue — the revenue your attribution model credits to this advertising, excluding sales tax and any shipping you charge the customer. If your conversions are leads rather than sales, enter the monetary value you assign to those leads; Google Analytics does exactly this by adding total goal value to ecommerce revenue.
3. 03Enter the ad spend. Media cost only: ROAS is a return on advertising spend, so adding agency retainers or salaries turns it into a different metric. If you want the fully-loaded version, that is marketing ROI, not ROAS.
4. 04Enter the ROAS as a ratio if you are planning rather than measuring — 5 means 5×, which is 500%. Leave it alone if you selected ROAS.
5. 05Enter your gross margin on the attributed revenue. This is the input that turns the ratio into a verdict, and it is the one people skip. Use revenue minus cost of goods as a percentage of revenue — not net margin, not markup.
6. 06Compare ROAS to break-even ROAS. Above the line, the campaign adds gross profit; below it, every dollar of media destroys gross profit no matter how impressive the ratio looks. Then subtract your per-order costs below the gross line — fulfilment, payment fees, returns, support — to find the ROAS you actually need, which will be higher than the break-even shown.

The formula.

The core identity is return on ad spend = attributed revenue ÷ ad spend, rearranged two ways: revenue = ROAS × ad spend, and ad spend = revenue ÷ ROAS. All three modes are the same statement and round-trip exactly: $60,000 over $12,000 is 5.00×; 5.00× on $12,000 gives back $60,000; and $60,000 at 5.00× gives back $12,000. The percentage output is simply the ratio multiplied by 100, so 5.00× is 500% — the notation Google Ads uses when you set a target. The profitability branch uses your gross margin. Break-even ROAS is its reciprocal: 1 ÷ 0.45 = 2.22×, because at a 45% margin you keep 45 cents of every revenue dollar and therefore need 2.22 revenue dollars to cover one media dollar. Break-even revenue restates that threshold in currency for the spend you entered: $12,000 ÷ 0.45 = $26,666.67. Gross profit after ad spend applies the margin to the actual revenue and subtracts the media: $60,000 × 0.45 − $12,000 = $27,000 − $12,000 = $15,000. Rounding stage is part of the contract. Every intermediate value is carried at full decimal precision and rounding happens only once, at the return boundary, to two decimal places. Nothing is rounded in between, and two outputs depend on that. Break-even revenue is computed as ad spend ÷ margin rather than ad spend × the displayed break-even ratio: the true value is $26,666.67, whereas multiplying $12,000 by the displayed 2.22 would print $26,640.00, an error of $26.67. Likewise the percentage is derived from the unrounded ratio, so a ROAS of 6.6645 displays as 6.66× and 666.45%, not 666.00%. The test suite asserts both cases specifically. Guards reject the inputs with no answer: ad spend must be above zero whenever it sits in the denominator, because a campaign with no spend has no meaningful return rather than an infinite one; ROAS must be above zero when solving for ad spend; and gross margin must be above 0% and at most 100%, because break-even ROAS is one divided by margin and is genuinely undefined at zero, while gross profit can never exceed the revenue it comes from.

A worked example.

Frequently asked questions.

References& sources.

1. [1]MASB / Common Language in Marketing Project — Universal Marketing Dictionary, entry "Return on Ad Spend" (Common Language in Marketing Project, 2022; Universal Marketing Dictionary Project, 2024): "Return on Ad Spend (%) = Sales Attributable to Ads ($) / Cost of Ads ($)", plus the note that early-2020s calculations "often included non-advertising-driven sales, inflating results" and that correctly calculated ROAS and iROAS are identical. Retrieved 2026-07-29.
2. [2]MASB / Common Language in Marketing Project — Universal Marketing Dictionary, entry "Return on Investment": "Return on investment (%) = Net profit ($) ÷ Investment ($) x 100", citing Farris, Bendle, Pfeifer & Reibstein (2010). Cited here for the revenue-versus-profit contrast with ROAS. Retrieved 2026-07-29.
3. [3]Farris, Paul W.; Bendle, Neil T.; Pfeifer, Phillip E.; Reibstein, David J. — Marketing Metrics: The Definitive Guide to Measuring Marketing Performance, 3rd ed., Pearson Education (ISBN 978-0-13-705829-7). Chapter 9 "Advertising Media and Web Metrics" and Chapter 10 "Marketing and Finance" (Net Profit, Return on Sales). Print reference — no free full text; edition, ISBN and chapter structure verified against the publisher's sample-pages PDF.
4. [4]Google Ads Help — "About Target ROAS bidding": target ROAS is "the average conversion value (for example, revenue) you'd like to get for each dollar you spend on ads", worked as "$5 USD in sales ÷ $1 USD in ad spend x 100% = 500% target ROAS". Retrieved 2026-07-29.
5. [5]Google Ads Help — "About return on investment (ROI)": "ROI is the ratio of your net profit to your costs", worked on a $200 product costing $100 to produce, six units sold on $200 of ad spend: ($1200 − $800) / $800 = 50%. The same campaign is a 600% ROAS. Retrieved 2026-07-29.
6. [6]Amazon Ads — "What is Return on Ad Spend? How to Calculate ROAS" (Advertising Library guide): ROAS is "the amount of revenue from an ad campaign, divided by the amount spent on the campaign itself"; "A 2:1 ROAS ratio … would mean a brand is making $2 to every $1 of ad spend"; ROAS is campaign-specific whereas ROI "takes much more of advertising spends or total advertising cost into account". Retrieved 2026-07-29.
7. [7]Google Analytics Help — "[UA] About the Cost Analysis Report": ROAS is calculated as "((ecommerce revenue + total goal value) / advertising cost)" — a bare ratio, with non-transactional goal value included in the numerator. Retrieved 2026-07-29.
8. [8]Microsoft Learn / Xandr — Online Advertising and Ad Tech Glossary (document date 2025-10-22). Cited for a documented absence: the glossary carries CPM, CPC, CPA, vCPM, eCPM, eCPC and eCPA but contains no ROAS entry, because ROAS is an advertiser-side outcome measure rather than an ad-serving pricing model. Retrieved 2026-07-29.