Free ROAS Calculator

Work out your ROAS — return on ad spend — from the revenue a campaign produced and what it cost. This return on ad spend calculator gives you the answer as a multiple, a ratio and a percentage at once, plus the matching ACOS. Or run it backwards: enter a ROAS to find the revenue a budget needs to produce, or the spend behind a revenue figure.

What Is ROAS (Return on Ad Spend)?

ROAS is the revenue a campaign is credited with, divided by what the campaign cost. Spend $5,000 and be credited with $20,000 of revenue and your ROAS is 4 — four dollars back for every dollar in. It is the standard headline metric for performance advertising because it is comparable across campaigns, channels and budgets in a way that raw revenue is not.

The phrase doing the heavy lifting there is credited with. ROAS is only ever as good as the attribution model that produced its numerator: a platform counts revenue it believes it caused, within its own attribution window, using its own view of the customer journey. That is rarely the same figure your accounting system reports for the same period, and two platforms will happily claim the same sale. A ROAS number inherits every assumption of whatever produced it, so treat it as a measurement of a campaign inside one reporting system rather than as a statement about your business as a whole.

The ROAS Formula

Ratio, Multiple or Percentage — Three Names for One Number

The same ROAS gets written three different ways, and people arrive at this calculator with all three in mind. They are not different metrics:

The percentage convention is not a quirk — it is what Google Ads uses. Google Ads’ own documentation expresses a target ROAS as a percentage and works the example as $5 USD in sales ÷ $1 USD in ad spend x 100% = 500% target ROAS, which is a 5x return (About Target ROAS bidding). Mixing conventions inside one spreadsheet is the most common ROAS reporting error there is: a column holding "4" beside a column holding "400", both labelled ROAS, and an average taken over the pair.

ACOS: The Same Number Upside Down

ACOS — advertising cost of sales — is ROAS inverted and expressed as a percentage of revenue:

ACOS = Ad Spend / Revenue × 100

A 4x ROAS is a 25% ACOS. A 2x ROAS is a 50% ACOS. A 1x ROAS is a 100% ACOS. Amazon Ads’ own guide defines it the same way — ACOS = (ad spend ÷ ad revenue) x 100— and states that "Return on ad spend (ROAS) is the inverse of Amazon ACOS" (What is advertising cost of sales (ACOS)?). ACOS is the default framing on Amazon and in a lot of retail media; ROAS is the default almost everywhere else. Lower is better for ACOS, higher is better for ROAS, and the only thing you need to watch when converting is the direction of the comparison.

There is one asymmetry worth knowing. When a campaign produced no revenue at all, its ROAS is a perfectly meaningful 0 — but its ACOS is undefined, not 0%, because you cannot express a cost as a share of a sale that never happened. This calculator prints a dash in that case rather than a 0% that would read as "free".

Why a ROAS Number Alone Cannot Tell You If You Made Money

ROAS compares revenue to ad spend and nothing else. It says nothing about what it cost you to produce and deliver the thing you sold. Take one campaign — $5,000 spent, $20,000 of revenue, a 4.00x ROAS — and run it through two different businesses:

Identical campaign, identical ROAS, opposite outcomes. The number that decides it is your break-even ROAS, and it is the reciprocal of your gross margin:

Break-even ROAS = 1 / Gross Margin

At a 50% margin that is 1 / 0.5 = 2.0x, so a 4x campaign clears the bar twice over. At a 20% margin it is 1 / 0.2 = 5.0x, so the same 4x campaign is a loss. This is also why the "Revenue after ad spend" tile in the calculator is called exactly that and not "profit" — revenue minus ad spend has not subtracted cost of goods, shipping, payment fees or overhead, and calling it profit is the specific mistake this section exists to prevent.

Your own break-even ROAS is 1 ÷ your gross margin — at a 40% margin you have to beat 2.5x before the campaign contributes anything. Work out your break-even ROAS from your margin — or from your price and COGS — and then judge this campaign against it.

How to Use This Calculator

1. Pick what you are solving for — the three tabs cover the three ways the same formula gets used: measuring a campaign, sizing the revenue a budget has to produce, and working back to the spend behind a revenue figure.
2. Enter the two values you have — paste straight from your ad platform; $, commas and spaces are stripped for you. The ROAS field accepts 4, 4x, 400% or 4:1 and treats them as the same number.
3. Read the result — you get the full triple (revenue, ad spend, ROAS), the same ROAS in all three conventions, the matching ACOS, and revenue after ad spend.
4. Compare it to your break-even — divide 1 by your gross margin and check the ROAS against that, because that is the comparison that decides whether the campaign made money.

What Counts as a Good ROAS?

This page quotes no benchmark, deliberately. An unqualified "a good ROAS is 4:1" is not merely unsourced — the arithmetic above makes it close to meaningless, because the identical 4x is comfortably profitable at a 50% gross margin and loses money at 20%. A figure that changes sign depending on a variable it does not mention is not a benchmark.

The platform whose sellers search hardest for a target number declines to give one. Amazon Ads’ own guide says: "There isn’t a definitive number for a good Amazon ACOS. It’s dependent on your industry, company size, and campaign frequency, among other variables." That applies exactly as well to ROAS, since the two are the same measurement.

What to do instead:

• Work out your break-even ROAS first — 1 divided by your gross margin. Below it you are losing money on every incremental sale, whatever the campaign dashboard says.
• Set a target above it, not at it — the gap between break-even and target is what pays for overhead, and gives you room for the sales the attribution model over-counted.
• Benchmark against yourself— export the last 90 days by campaign, product and channel, calculate the ROAS for each slice, and judge new spend against that distribution rather than against a number from someone else’s account.
• Remember the trade-off with volume — a very high ROAS often means you are under-spending on a profitable channel. The goal is total contribution, not the highest possible ratio.

ROAS vs ROI vs ACOS vs MER

• ROAS — revenue divided by ad spend, for one channel or campaign. Revenue, not profit.
• ROI — profit divided by total investment. It subtracts all the costs ROAS ignores, which is why the two can point in opposite directions on the same campaign. For the organic-channel version of this, see the SEO ROI Calculator.
• ACOS — the reciprocal of ROAS expressed as a percentage of revenue. Standard on Amazon and in retail media.
• MER — total revenue divided by total ad spend across every channel, also called blended ROAS. It is immune to attribution disputes because it ignores attribution entirely: no channel gets credited with anything, you just divide the two totals.
• CPA and CPL — what you paid per conversion or per lead, which is where ROAS lands when the sale is not immediate. See the Cost Per Acquisition Calculator and the Cost Per Lead Calculator.

These chain together: CPM → CTR → CPC → conversion rate → average order value → ROAS. A ROAS drop is always traceable to one link in that chain, which is why diagnosing it starts with finding which of the five moved rather than with the ROAS itself.

Common ROAS Mistakes

Frequently Asked Questions

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