January 15, 2026

How to Calculate ROAS and Know If Your Ads Are Profitable

You spent $2,000 on Facebook ads last month and generated $8,500 in revenue. Was that a good result? Without a framework, you're guessing. ROAS gives you a number that answers that question instantly — and tells you exactly how much room you have before ads start losing money. If you're running a SaaS business, our SaaS churn and LTV calculator can help you understand the long-term value of those acquired customers.

What ROAS Actually Measures

ROAS stands for Return on Ad Spend. It divides your advertising revenue by your advertising cost. A ROAS of 4.25 means you earned $4.25 for every $1 spent on ads. Unlike profit margin, ROAS doesn't account for product costs, shipping, or overhead — it answers one narrow question: is the ad itself generating more revenue than it costs?

This matters because most advertising platforms report revenue attributed to campaigns, but they don't tell you whether that revenue is profitable after fulfillment. ROAS is the first filter. Profit margin is the second.

The Formula Most People Get Wrong

The basic formula is simple: ROAS = Revenue from Ads / Ad Spend. But the tricky part is defining "revenue from ads." If someone sees your ad on Monday, clicks it, leaves, and returns three days later to buy directly — does that sale count? Most attribution models say yes, but last-click attribution gives all credit to the final touchpoint, which might be a branded search term, not the original ad.

For this calculator, use the revenue your ad platform reports. It's not perfect, but it's consistent across campaigns and gives you a baseline for comparison.

A Worked Example with Real Numbers

Suppose you run a Google Ads campaign for a SaaS product priced at $49/month. You spend $1,500 on ads and acquire 45 new customers in that period.

• Ad spend: $1,500
• Revenue: 45 customers × $49 = $2,205
• ROAS: $2,205 / $1,500 = 1.47

A ROAS of 1.47 means you earned $1.47 per ad dollar. If your cost to deliver the product is 40% of revenue ($882), your actual profit from these customers is $2,205 - $882 - $1,500 = -$177. The ads are technically generating revenue, but you're losing money. This is why ROAS alone doesn't tell the full story — you also need to know your margins.

Finding Your Break-Even Point

Break-even ROAS is the minimum return needed to cover all costs. Calculate it by dividing 1 by your profit margin. If your product costs $30 to deliver and sells for $100, your margin is 70%, and your break-even ROAS is approximately 1.43. Any ROAS above 1.43 means you're profitable on the ad spend itself. Below that, you're losing money even though revenue is coming in.

Most healthy e-commerce businesses target a ROAS between 3:1 and 5:1. SaaS companies with recurring revenue can often sustain lower initial ROAS because customer lifetime value makes up the difference over time. Our Stripe fee calculator can help you account for payment processing costs when calculating true margins.

The SaaS Scenario Nobody Talks About

If you sell a $49/month subscription and your churn rate is 5% monthly, the average customer stays about 20 months. That's $980 in lifetime revenue from a single acquisition. If your CAC is $120, your LTV:CAC ratio is 8.2:1 — excellent. But your first-month ROAS from that same customer is only $49/$120 = 0.41. A new manager looking at first-month ROAS would kill a campaign that's actually highly profitable over time.

This is the trap with ROAS in subscription businesses. It measures short-term return, not lifetime value. Always look at cohort data alongside ROAS when evaluating subscription campaigns.

When ROAS Misleads You

ROAS can be deceptive in a few scenarios. If you're running brand awareness campaigns, the revenue attribution is often delayed or incomplete — the ads work, but ROAS looks terrible in the short term. If you sell low-margin products, a 5:1 ROAS might still mean you're barely breaking even. And if you're comparing ROAS across different platforms, remember that each platform uses different attribution windows (Google defaults to 30 days, Facebook to 7 days).

The most honest use of ROAS is comparing it to itself over time on the same platform with the same attribution settings. Trend direction matters more than absolute numbers.

Frequently Asked Questions

What is a good ROAS for Google Ads?

A ROAS of 4:1 is considered good for most Google Ads campaigns. This means you earn $4 for every $1 spent. However, the threshold varies by industry and profit margins.

How do I calculate break-even ROAS?

Divide 1 by your profit margin. If your margin is 25%, break-even ROAS is 4:1. You need at least this return to cover costs.

Can ROAS be over 100%?

Yes. ROAS is expressed as a ratio or multiplier, not a percentage. A 10:1 ROAS means you earn $10 for every $1 spent. Some e-commerce campaigns achieve 20:1 or higher.

What is the difference between ROAS and ROI?

ROAS measures revenue per ad dollar. ROI measures profit per total investment. A campaign with 5:1 ROAS might still have negative ROI if product costs are high.

When to Trust ROAS and When to Look Deeper

Use ROAS for short-term campaign optimization — pause underperformers, scale winners. But don't use it as your only metric. Pair it with customer acquisition cost, lifetime value, and margin analysis. For subscription businesses, always look at cohort LTV alongside first-month ROAS. For e-commerce, factor in product margins, shipping costs, and return rates before making budget decisions.