ROAS calculator

How the ROAS calculator works

ROAS, return on ad spend, is the revenue your ads brought in divided by what those ads cost, both excluding VAT. Spend EUR 1,500 on Google Ads, get EUR 6,000 in revenue, and your ROAS is 4: every euro of advertising brought four euros back. Google Ads shows the same figure in its conversion value per cost column, and asks for it as a percentage when you set a target ROAS: a ROAS of 4 is 400 percent there.

That number on its own does not tell you whether you make money. For that you need your gross margin: what is left of a euro of revenue after the cost of the goods. At a 30 percent margin, EUR 6,000 of revenue leaves EUR 1,800 of gross profit. Take off EUR 1,500 of ads and EUR 300 remains. The calculator above runs the whole path; the table shows each step with the same example. If you do not know your margin yet, work it out first in the margin calculator.

A break-even ROAS calculator in one line

The break-even ROAS is 1 divided by your gross margin. The logic is short: each euro of revenue leaves your margin, and the ad has to be paid out of it. Keep 25 percent and a euro of revenue can carry at most 25 cents of advertising. That is a ROAS of 4. Above it you earn, below it you pay to sell.

An online shop also pays shipping and a payment fee on each order. Those costs sit outside the gross margin, yet they shrink what is left for the ads. Enter the number of orders and the cost per order in the calculator and the break-even moves with them. The margin calculator works out shipping and payment fees from Mollie, Stripe and Shopify Payments per order.

A good ROAS depends on your margin

A good ROAS sits above your break-even, with room for the profit you want to keep. To keep 10 percent of revenue after the ads, divide 1 by your margin minus 0.10. The last column shows what happens if your business cannot reclaim the VAT on its ads, as under a small business exemption in Belgium: each euro of ads then costs 1.21 euros.

If you do not have a sharp figure for your own margin, start from your sector. The table below gives gross and net margins of listed European companies per sector, from a January 2026 dataset of 6,560 companies. Net margin is what is left after every cost: staff, rent, marketing and tax. The gap between the two columns is the room your advertising has to fit in.

A small online shop buys at higher prices than a listed chain, so its margin is often lower. Use your sector as a first estimate and replace it as soon as you know your own costs. The calculator fills in a sector with one click.

POAS: profit per euro of advertising

POAS, profit on ad spend, divides the gross profit from your ads by what they cost. Where ROAS counts revenue, POAS counts what you keep, and its line always sits at 1, for every product and every sector. A POAS of 1.2 means each euro of ads brought EUR 1.20 of gross profit. Below 1 you lose money. Google Ads can report gross profit per campaign itself when you send cart data and add the cost of goods per product in Merchant Center. Without that link, read the POAS row in the calculator; it also takes off shipping and payment fees if you enter them.

ROAS per channel: Google Ads and Meta count differently

Google Ads credits a sale with data-driven attribution by default: the model spreads the sale over the clicks that came before it. Last click is still available; the old models such as first click and linear are gone. The click window is 30 days by default, so a sale 40 days after the click does not count, even when the customer came through your ad.

Meta announced a new way of counting clicks on 3 March 2026, rolled out from late March. A conversion counts as click-through only when someone clicked the link in your ad. Shares and saves fall under engage-through, and an engaged view on video now starts at 5 seconds instead of 10. Billing does not change. What that means for your reports is in our piece on Meta's click attribution change. What a click costs on each platform is in the guides to Google Ads cost and Facebook ads cost.

What you measure matters too. Since 15 June 2026, data from Google Analytics only reaches Google Ads when the visitor allowed advertising cookies; the consent mode change explains how to check your setup. A ROAS that drops right after a new cookie banner is often a measuring problem, not a campaign problem.

VAT, cross-border buyers and your ROAS

A business with a VAT number in an EU country other than Ireland gets its Google and Meta invoices without VAT. You self-assess the VAT at your own country's rate, 21 percent in Belgium and the Netherlands, 19 in Germany, 20 in France, and deduct it in the same return. Your ROAS does not change.

It does change for a business that cannot deduct VAT. In Belgium, a small business with turnover up to EUR 25,000 excluding VAT can use the exemption scheme: it charges no VAT and deducts none, but still pays the reverse-charged VAT on its ads. Each euro of advertising then costs EUR 1.21, and the break-even ROAS rises by 21 percent: 4.84 instead of 4 at a 25 percent margin. Other member states set their own thresholds; the calculator uses the standard rate you choose. Choose that the VAT on your ads is a cost, and the calculator adds it.

Selling to consumers in other EU countries, above EUR 10,000 a year in such distance sales you charge the VAT rate of the customer's country, usually declared through the One Stop Shop. Take each country's rate out of its own revenue before you divide, or your ROAS mixes 19 and 21 percent without telling you.

Four businesses, four sums

A small online shop. You sell ceramics, are VAT-exempt and spend EUR 300 a month on Meta. It brings in EUR 1,200, without VAT since you charge none. Your ROAS is 4. With the reverse-charged VAT your ads cost EUR 363, your 50 percent margin leaves EUR 600, so you keep EUR 237. Your break-even is 2.42.

An online shop that ships. You spend EUR 2,000 on Google Ads and make EUR 9,000 excluding VAT from 150 orders at a 40 percent margin. Shipping and payment cost EUR 8 per order, EUR 1,200 in total. Your ROAS of 4.5 looks comfortable, yet the order costs push your break-even from 2.5 to 3.75. You keep EUR 400. Tomorrow, check which products carry the margin and move budget to those product groups.

A service business. An ad brings a lead, not a sale, so you count what a lead is worth. A renovation company pays EUR 1,000 for ten leads; two sign and bring EUR 2,000 each. That is EUR 4,000 in revenue and a ROAS of 4. Choose leads in the calculator and enter those three numbers. At a 35 percent margin on the work the break-even is 2.86, and the campaign keeps EUR 400, exactly the 10 percent target. Send those clicks to a landing page that makes the same promise as the ad; how Google Ads works for local businesses explains the set-up.

A ten-person company on two channels. Google Ads costs EUR 3,000 and claims EUR 15,000; Meta costs EUR 2,000 and claims EUR 8,000. Together EUR 23,000, while your books show EUR 18,000 in revenue that month. Divide all revenue by all ad spend and you get a total ROAS of 3.6. It counts nothing twice, though it includes sales that would have come without ads. At a 35 percent margin EUR 1,300 is left. To set the overall budget against your revenue, use the marketing budget calculator.

What the calculator leaves out

• Fixed costs such as salaries, rent and software. You pay them with or without ads, out of the profit the calculator shows.
• Returns and cancellations. Take them off your revenue first; if your account counts conversion value including returns, the platform's ROAS reads high.
• Customers who come back. A first sale at a loss can pay off when the customer buys again. Work that out separately and carefully.
• Brand awareness from ads that were seen but not clicked.
• Your VAT return itself. Your accountant confirms which scheme applies to you.