How to Calculate ROAS, CPA and LTV for Social Media Ads (With Examples)

Every social media ad campaign either makes money or loses it, and the only way to know which is happening is to track three numbers. Ignore them and you're gambling with a nicer interface. Track them and you're running a business.

Cost Per Acquisition (CPA)

CPA is simply what one paying customer costs you.

Formula: CPA = Total Ad Spend / Number of Conversions

If you spend $300 on ads and get 10 sales, your CPA is $30. That number only means something next to your price: sell a $49 product at a $30 CPA and you're making $19 profit per sale before other costs. The goal isn't to hit some arbitrary "good" CPA — it's to keep it comfortably below what you can afford given your margins.

Return on Ad Spend (ROAS)

ROAS is the universal scoreboard for campaign performance.

Formula: ROAS = Revenue From Ads / Total Ad Spend

A ROAS of 4.0 means $4 in revenue for every $1 spent. Most sustainable ad campaigns aim for a minimum ROAS of 3.0, though the real threshold depends on your profit margin — a business with thin margins needs a higher ROAS to actually be profitable than one with fat margins does.

Lifetime Value (LTV)

LTV is the number that changes everything else, and it's the one most people skip.

Definition: the total amount a customer spends with you over the entire relationship, not just their first purchase.

Here's why it matters: imagine a $29 ebook with a $12 CPA. On the first sale alone, that's a healthy $17 profit. But if roughly a third of buyers eventually buy a second $29 guide, your real average LTV climbs closer to $39 — which means you could actually afford to spend $20, $25, even $30 to acquire that same customer and still come out ahead once repeat purchases are counted. LTV is what lets you justify a higher CPA than competitors who are only looking at the first sale.

A worked example

Say you're running ads for a $29.99 social media strategy guide:

• Ad spend: $200
• Conversions: 8 sales
• CPA = $200 / 8 = $25
• Revenue: $240 (8 × $29.99, rounded)
• ROAS = $240 / $200 = 1.2

At first glance, 1.2 ROAS looks weak against the 3.0 benchmark. But if 3 of those 8 buyers go on to buy a second guide at $29.99 within the next quarter, your real LTV per customer rises from $30 to roughly $41 — and your effective ROAS against total revenue generated (not just first-purchase revenue) climbs well past 1.2. This is exactly why tracking only first-purchase ROAS can make a genuinely profitable campaign look like a loser.

Where this connects to retargeting

Once you're tracking these numbers, the fastest lever to improve them isn't usually new creative — it's smarter targeting of people who already know your brand. Segmenting retargeting audiences by how recently someone engaged (rather than lumping everyone into one audience) is currently lifting ROAS 40–70% with no increase in spend, according to 2026 retargeting data. The Meta Ads retargeting playbook covers exactly how to set that segmentation up.

The takeaway

CPA tells you what a customer costs. ROAS tells you if a campaign is profitable today. LTV tells you what a customer is actually worth — and it's the number that should be shaping how aggressively you bid, not the other two alone.

This is one piece of a larger system — see our full social media marketing strategy guide for how it fits with budget allocation between organic and paid.