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The Honest ROAS Calculator.
Two numbers in, your ROAS out - add total revenue and you get blended MER too. Then the layer other ROAS calculators skip: the four things the number cannot tell you, and where to get each answer. It is the ROAS calculator that tells you when ROAS is lying.
Built by HoloGrowth - 50+ DTC brands, $50M+ partner revenue. No email, no gate - the math runs entirely on this page.
Your spend and revenue in, the real picture out.
Pull all three numbers from the same date range - and keep total revenue from your backend, never from an ad platform.
Total paid media: "Amount spent" in Meta Ads Manager plus "Cost" in Google Ads (plus TikTok and the rest), same date range, added together
What the platforms claim: "Purchase conversion value" in Meta Ads Manager plus "Conversion value" in Google Ads, same date range. Each platform grades its own homework - that is the point of this page
Optional - unlocks blended MER. Total revenue for the same date range from your own backend ("Total sales" in Shopify analytics), not from any ad platform
You will notice the calculator never shows a green verdict. That is deliberate - no ROAS is good or bad on its own. The bar it has to clear lives in your margin structure: the Breakeven ROAS Calculator computes it. And whether the number is even real is a separate question - The Agency Incentive Problem explains why it often is not. More free tools: the full tools library.
How ROAS and MER actually work.
ROAS = revenue attributed to ads ÷ ad spend
Worked example: $50,000 of monthly ad spend, and the platforms credit themselves with $150,000 of revenue. ROAS: $150,000 ÷ $50,000 = 3x. Every $100 of claimed revenue cost $33.33 in ads - which is why the calculator also shows spend as a share of revenue, the version of the number your margin has to beat.
Add total revenue and you get MER - marketing efficiency ratio: total store revenue ÷ total ad spend. Same month, $220,000 of total revenue: MER = $220,000 ÷ $50,000 = 4.4. No attribution model involved - every dollar the store earned against every dollar ads spent.
Two ratios, two lenses. ROAS is a channel number built on the platforms' own claims. MER is a business number built on your books. Neither one tells you whether the ads made a profit - that takes your margin structure, and it is exactly where most ROAS conversations quietly fall apart. The next two sections cover both gaps.
ROAS vs MER: the platform's opinion vs your books.
The two ratios disagree by construction. Knowing why is more useful than either number alone.
The channel lens
Platform-attributed revenue divided by that platform's spend. It answers "which channel, which campaign" - but the numerator is self-graded: each platform attributes orders to itself, and nobody reconciles the claims. In the accounts we've audited, Google typically overstates its contribution by 80-90% and Meta typically understates by 20-80%.
The business lens
Total revenue divided by total ad spend, straight from your books. Nothing to argue with - but no channel detail either, and it counts revenue ads never touched: organic, email, repeat orders. MER can look healthy while every incremental ad dollar loses money, and vice versa.
Read them together. MER is the number you can defend to your accountant; ROAS is the platforms' opinion of where the credit belongs. And when the platform claims, added together, exceed what your store recorded, you are not looking at performance - you are looking at double counting. The calculator above flags exactly that case.
What your ROAS does not tell you.
The division is the easy part. These four questions decide whether the answer means anything - and each one has a free tool or write-up attached.
Whether the revenue is real
The numerator is the platform grading its own homework. In the accounts we've audited, Google typically overstates its contribution by 80-90% and Meta typically understates by 20-80% - here is why that happens structurally. A ROAS built on an inflated numerator is not a performance metric, it is a sales pitch.
Whether the buyers are new
A branded-search click from someone already coming to buy, or a repeat order from a customer you paid to acquire last year, counts exactly like a cold-traffic first purchase. The better your retention, the more inflated your ROAS - one audited brand's 8x was a 2x once brand search and repeat buyers came out.
Whether the revenue makes money
ROAS is a revenue ratio; profit lives in contribution margin. At a 20% contribution margin before ads, a 4x ROAS still loses money after ad spend - at a 60% margin, a 2x leaves 10% of revenue as profit. The ROAS you NEED is computable from your own costs: run the Breakeven ROAS Calculator.
Which target it has to clear
There are two targets, not one. Until ad-driven revenue covers your fixed costs - salaries, software, rent - your first tier of spend needs a higher ROAS than plain breakeven, which is why an account "above breakeven" can still lose money on the P&L. The two-tier math, worked through.
Every ROAS calculator on the internet does the division. This one exists for the four questions after it - because the division was never the hard part. Knowing when the answer is lying to you is.
Already at $1M+/year and spending $30K+/month on ads?
You have your ROAS. Now find out how much of it is real.
This page computes the number and names its blind spots. It cannot check your account for brand-search harvest, repeat-buyer inflation, or double-counted attribution - at your spend, that gap is where the money goes. On a free 30-minute call we sanity-check your numbers against your P&L and name your most likely constraint live.
For brands at $1M+ per year spending $30K+/month on ads. 8 strategy calls a week.
ROAS, answered honestly.
ROAS (return on ad spend) is revenue attributed to ads divided by ad spend. $50,000 of spend that the platforms credit with $150,000 of revenue is a 3x ROAS. The load-bearing word is attributed: the numerator comes from each platform's own attribution model, which is why the same month shows a different ROAS in Meta, in Google, and in your backend.
There is no universal benchmark, and anyone quoting one is skipping the math. Whether a ROAS makes money depends on your margin structure: at a 20% contribution margin before ads, a 4x ROAS still loses money after ad spend, while at a 60% margin a 2x leaves 10% of revenue as profit. The useful question is not "what is good" but "what do I need" - your AOV, COGS, shipping, fees, and fixed costs set that number, and the Breakeven ROAS Calculator computes it.
ROAS divides platform-attributed revenue by spend - it trusts the platforms to say which orders they drove. MER (marketing efficiency ratio) divides total revenue by total ad spend - it trusts nothing and counts everything. ROAS overstates ad performance when platforms overclaim; MER blurs channel-level performance because it includes revenue ads never touched, like organic, email, and repeat orders. Read them together: MER comes from your own books and is defensible, ROAS is the platforms' opinion of where the credit belongs.
ROAS is a measurement - what the ads returned. Breakeven ROAS is a threshold - the return where an ad-driven sale stops losing money, set by your AOV and variable costs. A 3x ROAS is meaningless until you know whether your breakeven is 1.4x or 2.9x: the first is comfortable, the second is a loss once you want margin left over. This page measures; the Breakeven ROAS Calculator sets the bar.
Because each platform attributes orders to itself using its own rules and windows, and nobody reconciles the claims. In the accounts we've audited, Google typically overstates its contribution by 80-90% and Meta typically understates by 20-80% - here is why that happens structurally. Add the platform numbers together and they can exceed what the store recorded. The number to trust is the one from your own books: blended MER, plus ad-attributed revenue cross-checked against backend new-customer revenue.
No. The math runs entirely in your browser - nothing you type is stored or sent anywhere, and no email is required. It is free because the division was never the hard part; knowing when the answer is lying to you is. When you get to that point, that is what the free Strategy Call is for.
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Free ROAS Calculator (+ MER) by HoloGrowth: https://hologrowth.com/tools/roas-calculator/