The first number most store owners look at in their ad dashboard is ROAS: return on ad spend. A figure like 4x looks excellent, but on its own it doesn’t tell you the campaign is profitable. You can be losing money at 4x, and doing well at 2.5x. The difference lies entirely in your profit margin and in how the platform measures.
What ROAS is and how to calculate it
The formula is simple: the sales value the platform attributes to your ads, divided by what you spent on them.
ROAS = Revenue from ads ÷ Ad spend
Example: you spent 10,000 and the platform recorded 40,000 in sales, so your ROAS is 4 — every unit you spent brought back four in sales, not in profit.
Break-even: the number to know before any campaign
From those four units you pay for the product, shipping, payment fees and packaging. What’s left is your margin. A campaign breaks even when that margin exactly covers the cost of the ad. The formula:
Break-even ROAS = 1 ÷ Profit margin (after product, shipping and fees)
| Profit margin | Break-even ROAS | What it means |
|---|---|---|
| 20% | 5.0 | You need 5 in sales for every 1 in ads just to break even |
| 30% | 3.33 | Below 3.33 is a loss, above it is profit |
| 40% | 2.5 | A comfortable margin that leaves room to scale |
| 50% | 2.0 | Plenty of room to test new audiences |
That’s why there’s no universal “good ROAS”. A store with a 20% margin loses money at 4x, while a store with a 50% margin profits at 2.5x. Work out your break-even number once, and make it the line you measure every campaign against.
Calculate your ads' break-even point
Enter your product price and cost to find the minimum return on ad spend you need to avoid losing money, and the most you can pay per order.
- Profit margin
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- Max cost per order
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- Your current ROAS
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This is an estimate and doesn't include returns, cancelled orders or fixed costs.
Why platform ROAS differs from your real sales
Add up the ROAS from Meta, Google and Snapchat and you’ll often find the platforms claim more sales than your store actually recorded. That’s normal, and the reasons are well known:
- Attribution windows: each platform claims a purchase if it happens within days of a click or view of its ad — even if the customer bought after seeing an ad on another platform.
- View-through conversions: some settings count purchases from people who saw the ad without clicking it, which inflates the number.
- Customers who would have bought anyway: retargeting and branded search ads reach people close to buying, so their return looks very high.
- Cancellations, returns and cash on delivery: the platform counts the order when it’s placed, not after it’s paid for and kept.
The more honest number: blended return on all spend
Instead of chasing each platform’s ROAS, look weekly at one number from your own store: total real sales divided by total ad spend across every platform. It’s sometimes called MER, or blended ROAS. No platform’s attribution affects it, and it answers the real question: are your ads, together, growing the store?
How to use ROAS in your decisions
- Work out your break-even ROAS from your real margin, and keep it in front of you.
- Compare campaigns within the same platform using that platform’s ROAS — it measures them all the same way.
- Compare platforms with each other, and judge overall growth, using the blended return from your store — not platform numbers.
- Separate retargeting and branded search from new-customer campaigns; the high return on the first doesn’t mean they bring growth.
- Review returns and cancelled orders monthly and subtract them from sales before judging any campaign.
When we review our clients’ ad accounts, we always start from one question: what’s the store’s margin? Because a return that looks excellent in the ad dashboard can be covering a loss — and the reverse is true too.
