What is the ROAS formula?

ROAS = revenue from advertising ÷ advertising spend. Spend $2,000 and book $9,000 in attributed revenue and your ROAS is 4.5. The result is a ratio, not a percentage, though platforms often display it as 450 %. Both mean the same thing.

What is ROAS in simple terms?

It is the revenue your advertising brought in for every unit of currency you put into it. Nothing more. It says nothing about cost of goods, shipping, returns or overheads, which is why a campaign can post a healthy ROAS and still lose money on every order.

Is ROAS the same as ROI?

No. ROAS divides revenue by ad spend; ROI divides profit by total investment. ROAS of 4.0 sounds like a 300 % return but is not one, because the numerator still contains the cost of the goods you sold. On a 25 % margin, a ROAS of 4.0 is exactly break-even.

What ROAS do I need to break even?

Divide one by your gross margin. At a 40 % margin you need 2.5; at 20 % you need 5.0. That figure is the floor, not the target, because it covers only variable cost. Rent, salaries and software still have to come out of whatever sits above it.

ROAS Formula: How to Calculate Return on Ad Spend

One division, three answers. Why that happens, and which of them you should act on.

A campaign I run for our wholesale business posted a ROAS of 6.1 in the Google Ads interface last quarter. Our analytics tool said 4.4. The accounting export, once returns had cleared, said 3.8. Same campaign, same period, three numbers. None of them was wrong.

What is ROAS, and where the division happens

Return on ad spend is a ratio: what advertising brought in, over what advertising cost. That is the whole of it. The formula carries no opinion about margin, returns or the rent you pay, which is exactly why it travels so well between platforms and so badly into a profit-and-loss statement.

ROAS = revenue from advertising ÷ advertising spend

Spend $2,000, book $9,000 in attributed revenue, and the answer is 4.5. Some dashboards print 450 % instead. Same number, different clothing.

Why one campaign reports three different figures

The formula is fixed. What goes into it is not, and three decisions move the result more than any optimisation you will do this month.

Attribution window 7 vs 28 days

Revenue basis gross vs net of returns

Cost basis media only vs full cost

A longer window credits the campaign with purchases that took two weeks to happen. Gross revenue counts orders that came back. Media-only spend quietly drops the agency fee. Each choice is defensible on its own, and stacked together they produced the gap between 6.1 and 3.8 in our account. Pick one definition, write it down, and use it everywhere. Consistency beats accuracy here, because nobody is comparing your number to an external truth — they are comparing it to last month.

Revenue over spend, or profit over everything

ROAS puts revenue over ad spend. ROI puts profit over the whole investment, and the gap between them is whatever your goods cost, which is why a 4.0 can be comfortable on one product and break-even on another. A full comparison, with the margin table and the vocabulary problem that comes with it, sits in ROI vs ROAS.

Running the formula backwards

The useful move is the inverse. Instead of measuring what your ROAS was, derive what it has to be. Divide one by your gross margin and you have the floor.

60 % margin 1.7x

40 % margin 2.5x

25 % margin 4.0x

20 % margin 5.0x

That floor covers variable cost and nothing else. Rent, salaries and software sit above it, so a break-even ROAS is a stopping line, not an objective. Two products in the same shop can have floors that differ by a factor of three, which makes a single account-wide target meaningless. Work it out per product group. The break-even ROAS calculator does the division and hands you the matching maximum CPC, which is the number you can actually put into a bidding strategy.

When the target belongs in the bidding strategy

Google Ads will bid towards a ROAS target for you. It needs conversion values to do it, and it needs enough of them: the documentation is explicit that the algorithm predicts value per click from past conversions, so a campaign with a handful of sales a month has nothing to learn from. Feed it the wrong value and it optimises faithfully towards the wrong thing. Sending contribution margin instead of order value is the single change that moved our account most, and it took an afternoon.

Frequently asked questions

What is the ROAS formula?: ROAS = revenue from advertising ÷ advertising spend. Spend $2,000 and book $9,000 in attributed revenue and your ROAS is 4.5. The result is a ratio, not a percentage, though platforms often display it as 450 %. Both mean the same thing.
What is ROAS in simple terms?: It is the revenue your advertising brought in for every unit of currency you put into it. Nothing more. It says nothing about cost of goods, shipping, returns or overheads, which is why a campaign can post a healthy ROAS and still lose money on every order.
Is ROAS the same as ROI?: No. ROAS divides revenue by ad spend; ROI divides profit by total investment. ROAS of 4.0 sounds like a 300 % return but is not one, because the numerator still contains the cost of the goods you sold. On a 25 % margin, a ROAS of 4.0 is exactly break-even.
What ROAS do I need to break even?: Divide one by your gross margin. At a 40 % margin you need 2.5; at 20 % you need 5.0. That figure is the floor, not the target, because it covers only variable cost. Rent, salaries and software still have to come out of whatever sits above it.

Background & sources

How Google Ads bids towards a ROAS target and what data it needs to do so: Google Ads Help – «About Target ROAS bidding».
What a conversion value is and how it reaches the platform, which decides what the numerator of your ROAS contains: Google Ads Help – «About conversion values».
Industry averages, useful as a rough orientation and nothing more: WebFX – «Average ROAS by Industry».

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