What Is the ROAS Formula? How To Use the ROAS Formula

The ROAS formula is used to determine the total revenue generated for every dollar spent on advertising. This calculation is often expressed as a ratio, such as 4:1, where for every dollar spent on advertising, you earn $4 in revenue.

The ROAS formula helps ecommerce businesses quantify the financial impact of their marketing initiatives. In this guide, you will learn how to use the return on ad spend formula, how to calculate it across multiple platforms, and how to apply these actionable insights to optimize your budget allocation for growth.

What is ROAS?

Return on ad spend (ROAS) measures how much revenue is produced for every advertising dollar spent. Although other key metrics, such as conversion rates, click-through rates, and impressions, provide insight into the customer journey, ROAS focuses directly on financial results. It tells you exactly how well your advertising investment is driving revenue.

ROAS is an essential metric for evaluating campaign performance across your ad platforms, helping you distinguish between productive advertising efforts and those causing wasted spend.

What is the ROAS formula?

The ROAS calculation is:

ROAS = Revenue from ads / Ad spend

To get an accurate result from the ROAS formula, you must clearly define your inputs:

• Revenue generated. This is the total revenue generated from your advertising initiatives. In digital marketing, tracking tags help attribute revenue to the ad channel responsible for driving the sale.

• Ad spend. Ad spend is the total advertising costs paid to ad platforms like Facebook, Google, or TikTok. Although some brands include hidden costs like ad management fees or creative production, the standard ad spend calculation only includes the direct advertising spend.

For example, if an ad campaign for a new product line produces $20,000 in revenue and the ad spend was $4,000, the ROAS calculation is:

ROAS = $20,000 / $4,000 = 5

In this case, your ROAS is 5:1, meaning you generated $5 in revenue for every dollar spent on advertising. 

Return on ad spend calculator

You can find your return on ad spend by using a ROAS calculator—a dedicated spreadsheet designed to model expected campaign outcomes. The calculator below includes both a blank template for your own data and a completed example to guide your inputs. It contains three tabs: instructions, a worked example, and a blank template you can fill in. Follow the instructions to run your own calculations.

How to use ROAS

• Set targets
• Monitor trends
• Compare ROAS on various channels
• Use attribution reporting

Calculating your return on ad spend can help you identify top-performing and low-performing campaigns so that you can refine your advertising strategies and adjust your spend accordingly. An acceptable ROAS varies based on your company’s margins, customer lifetime value, and business goals. Here are ways to use ROAS to optimize your paid advertising.

Set targets

On an episode of Shopify Masters, Dan Demsky, founder of Unbound Merino, says that he sets a minimum ROAS target (for example, 3:1) and only increases ad spend once a campaign has proven its efficiency by consistently hitting or exceeding the target ratio. If the performance dips below the target ROAS, he halts spending increases on the ad. 

To employ this strategy, you can use Shop Campaigns, Shopify’s pay-per-sale advertising program. Shop Campaigns displays ROAS as sales divided by ad spend, and you can set targets and reallocate budget from low-ROAS campaigns to those with higher returns.

Monitor trends 

Consistently monitoring your ROAS lets you understand the long-term profitability trends of your paid ad program. With Shopify marketing analytics, you can track return on ad spend across all marketing activities and campaigns from the Marketing page on your dashboard. This gives you past performance data and real-time visibility into campaign profitability.

Compare ROAS on various channels

To get a full picture of your ad spend efficiency, compare ROAS across multiple channels. 

A high ROAS on Google Search Ads may result from customers who have already decided to buy and are actively searching for your product. A similar ROAS on a social platform like Meta or TikTok might be more valuable because it suggests your demand generation efforts are introducing new users to the brand and convincing them to buy without prior search intent. Understanding where a user is in the customer journey lets you weigh those returns differently.

Use attribution reporting

You can calculate ROAS using different attribution models—such as first-touch, last-touch, and last non-direct—to understand which touchpoints result in sales that drive revenue.

• First-touch attribution. The first-touch attribution model credits the campaign that first brought the customer to your site. This identifies the ads that are excellent at brand awareness but might not result in an immediate sale.

• Last-touch attribution. This model gives 100% of the credit to the final interaction. This highlights your “closers”—the bottom-of-funnel tactics that close the sale.

• Last non-direct attribution. This model filters out users who came directly to your site, letting you see the last marketing effort that actually influenced the purchase journey.