ROAS Calculator

A campaign that brings in four times its cost sounds like a winner, but whether it actually makes money depends on what each sale leaves you after product costs. This ROAS calculator gives you the headline return on ad spend, the same ratio that Target ROAS bidding in Google Ads aims for, and then checks it against your margin, so you can see the break even point and the gross profit left once the ad bill is paid.

Quick answer: A ROAS calculator divides revenue from ads by ad spend, so £12,000 of sales from £3,000 of spend is a ROAS of 4.00x. Break even ROAS is 1 ÷ gross margin, which means a 40% margin needs 2.50x just to cover the cost of the goods sold through the ads.

What Is ROAS?

ROAS stands for return on ad spend. It is simply revenue from ads ÷ ad spend. Spend £3,000 and record £12,000 of sales from those ads and your ROAS is 4.00x, often written as 4:1 or 400%. Ad platforms report it because it is quick to measure and easy to compare between campaigns.

ROAS is a revenue measure, not a profit measure. Your break even ROAS is 1 ÷ gross margin. With a 40% margin you need 2.50x just to cover the cost of the goods you sold through the ads. Anything above that line is gross profit; anything below it means the ads are costing you money.

How to Use the ROAS Calculator

Step 1: Enter Revenue and Ad Spend

Choose your currency, then type the revenue your ads produced and what you paid for them over the same period. Use one campaign or a whole month, as long as both numbers cover the same dates.

Step 2: Add Your Gross Margin

Enter the share of each sale left after product, packaging and delivery costs. If you only know your cost and selling price, the profit margin calculator turns them into a margin percentage you can paste straight in here.

Step 3: Set a Target ROAS

If you work to a goal, such as 3x, type it in. The calculator shows the revenue you would need at your current spend, or the spend you could afford at your current revenue.

Step 4: Read the Results

You will see ROAS as a ratio and a percentage, your break even ROAS, gross profit after ad spend and the ad cost of sale, which is spend as a share of revenue. The green or red panel tells you at a glance whether the ads are paying for themselves.

Break Even ROAS by Margin

Leah sells hand poured candles with a 40% margin. Her Meta ads cost £3,000 last month and brought in £12,000, a 4.00x ROAS. Her gross profit on those sales is £4,800, so after the ad bill she keeps £1,800. If she cut her prices and her markup on each candle dropped, the margin would fall and her break even ROAS would rise, as the table below shows.

Gross margin	Break even ROAS	Max ad cost of sale
20%	5.00x	20%
30%	3.33x	30%
40%	2.50x	40%
50%	2.00x	50%
60%	1.67x	60%

Platform ROAS often counts sales that would have happened anyway, such as people who already knew your brand. Comparing it with your own sales records, and learning how gross margin is worked out for your products, gives a truer picture before you raise a budget.

ROAS Calculator Terms You Should Know

These advertising terms explain each result the ROAS calculator produces, helping you judge whether a campaign is genuinely profitable once the cost of goods is counted.

Break-even ROAS

The return on ad spend at which gross profit from ad-driven sales exactly matches the advertising cost, found by dividing 1 by the gross margin. Campaigns running below it lose money even when their revenue looks healthy.

Advertising cost of sale

Ad spend divided by the revenue those ads produced, shown as a percentage. It is the reciprocal of ROAS, so a return of 4.00x corresponds to an advertising cost of sale of 25%, and a lower figure is better.

Target ROAS bidding

An automated bidding strategy that adjusts bids to achieve a chosen average return on ad spend across a campaign. Setting the target above break-even helps protect profit, although very high targets can sharply limit sales volume.

Attribution

The method of assigning credit for a sale to the ads or channels a customer interacted with beforehand. The model chosen, such as last click or data-driven, changes how much revenue each campaign appears to generate.

Return on investment

Profit divided by the total cost of an activity, expressed as a ratio or percentage. Unlike ROAS, which looks only at revenue, it accounts for product and other costs, giving a truer view of whether advertising adds to profit.

Frequently Asked Questions