What is this ROAS calculator?
A free, browser-based calculator for ROAS — return on ad spend. Enter the revenue your ads generated and the ad spend, and it returns the ROAS as both a ratio (e.g. 5×) and a percentage (500%). Add your gross margin and it also derives the break-even ROAS, the profit on ad spend (POAS), and the net profit after the ad spend, so you can see whether a campaign is actually making money rather than just driving revenue. Everything runs locally in your browser, so your numbers are never uploaded.
How ROAS is calculated
ROAS is simply the revenue attributed to your ads divided by the ad spend: ROAS = revenue ÷ ad spend. A ROAS of 5× (500%) means every $1 of ad spend brought back $5 of revenue. Because it is revenue-based, it does not by itself tell you whether the ads are profitable — that depends on your margin, which is where the break-even ROAS comes in.
- ROAS = revenue ÷ ad spend (a ratio; 5× is the same as 500%).
- Break-even ROAS = 1 ÷ gross margin — the ROAS at which ads stop losing money.
- POAS = gross profit ÷ ad spend = ROAS × gross margin — the profit-based view.
Break-even ROAS and target ROAS
The single most useful companion to ROAS is the break-even ROAS: 1 ÷ gross margin. If your gross margin is 25%, you need a ROAS of 4× just to break even on the ad spend; at 40% margin, break-even drops to 2.5×. Anything above break-even is profit; anything below is a loss. To set a target ROAS, decide how much profit you want the ads to contribute and work back from the break-even point — a target meaningfully above break-even leaves room for profit and for the inevitable noise in attribution.
ROAS vs ROI vs POAS
These three are easy to confuse. ROAS divides revenue by ad spend. ROI divides profit by ad spend (and often includes more than just the ad cost). POAS sits in between, dividing the gross profit by ad spend — the same as ROAS multiplied by your gross margin. A campaign can post a strong 6× ROAS yet a POAS below 1× if margins are thin, meaning it loses money despite the impressive revenue multiple. Looking at the revenue ratio and the profit ratio side by side is the fastest way to avoid that trap.
Pitfalls to watch for
- Revenue, not profit: a high ROAS on low-margin products can still lose money. Use the margin field to check POAS.
- Attribution matters: the same campaign can show very different ROAS depending on the attribution window and model.
- Ignores LTV: ROAS counts the first purchase only. Acquisition campaigns may look weak until repeat revenue is included.
- Blended vs channel: a blended ROAS across all channels can hide a few unprofitable campaigns. Break it down.
Common use cases
- Checking whether a paid campaign cleared its break-even ROAS this month.
- Setting a target ROAS for a new channel based on your gross margin.
- Comparing the revenue ratio (ROAS) against the profit ratio (POAS) before scaling spend.