How to Track ROAS Across Meta, Google & TikTok Ads

A practical guide for Shopify merchants

If you’re running ads on Meta, Google, and TikTok, you’ve probably seen three different ROAS numbers for the same day. That’s normal—and it’s exactly why many merchants struggle to make confident budget decisions.

This guide gives you a practical, repeatable way to track ROAS across platforms, understand why numbers don’t match, and set up a reporting approach that’s consistent enough to guide action.

What ROAS really means

ROAS = Revenue attributed to ads / Ad spend.

Two important notes:

1. ROAS is attribution-based. It depends on which orders you count as “from ads.”
2. ROAS changes by platform rules: attribution windows, click vs view attribution, and event matching quality.

The goal isn’t to force all platforms to show the same ROAS. The goal is to:

• Useone “source of truth” for revenue, and
• Useconsistent rules when comparing performance across channels.

Why ROAS numbers don’t match across platforms

Here are the most common reasons Meta / Google / TikTok ROAS differs:

• Different attribution windows

  Example: Meta often uses 7-day click (and sometimes view-through), Google frequently uses longer click windows, and TikTok varies by setup.

• Different attribution models

  Some platforms assign credit more generously, others are stricter.

• Different tracking methods

  Pixel-only vs Pixel + server-side tracking changes the number.

• Different event definitions

  “Purchase value” might include taxes/shipping on one platform and not on another.

• Cross-device + privacy loss

  Users see ads on mobile and buy on desktop. Without strong matching, some conversions disappear or get misattributed.

The best mental model: one truth + two views

A strong setup usually has:

One source of truth for revenue & orders

For Shopify merchants, that’s typicallyShopify orders (gross or net—choose one and stick to it).

Two views of ROAS

1. Platform ROAS (optimization view)

   Use each platform’s ROAS to optimizeinside that platform (bidding, creatives, audiences).

2. Blended ROAS (business decision view)

   Use a unified model to decidecross-channel budgets.

Step-by-step: how to track ROAS across Meta / Google / TikTok

Standardize time range, time zone, and currency

Before comparing anything, make sure:

• Sametime zone (Shopify vs ad accounts)
• Samecurrency
• Same date range (e.g., Last 7 days / Last 30 days)

This alone eliminates a lot of fake “discrepancies.”

Use consistent UTMs on every campaign

UTMs are the simplest cross-platform glue. A clean baseline:

• utm_source = platform (facebook / instagram / google / tiktok)
• utm_medium = paid_social / paid_search
• utm_campaign = campaign_name_or_id
• utm_content = creative_id (optional but helpful)

Example:

Verify purchase events are correct

Checklist:

• Pixel installed & firingPageView / ViewContent / AddToCart / InitiateCheckout / Purchase
• Purchase event includesvalue andcurrency
• Deduplication configured if using both browser + server events

If purchase value is missing or wrong, ROAS becomes meaningless.

Add server-side tracking where possible

If you rely only on browser pixels, you’ll lose attribution due to ad blockers and privacy restrictions. Server-side tracking helps recover more conversions.

• Meta: Conversions API (CAPI)
• TikTok: Events API
• Google: Enhanced Conversions (and server-side via GTM server if possible)

You don’t need perfection—just aim to reduce “missing conversions.”

Align attribution settings for fair comparison

You can’t fully match attribution across platforms, but youcan make comparison fairer:

• Choose one primary comparison window (example: 7-day click)
• Consider turning off view-through conversions for comparison reports (optional)
• Keep the setting consistent month to month

Then track platform ROAS under the same comparison rule.

A simple reporting framework you can trust

A practical weekly reporting table includes:

1. Ad Spend (by platform)
2. Shopify Revenue (total)
3. Attributed Revenue (by UTM source)
4. Platform-reported conversions & ROAS
5. Blended ROAS = Shopify total revenue / total ad spend
6. MER (Marketing Efficiency Ratio) = Shopify revenue / total marketing spend (ads + tools)

How to use it:

• IfBlended ROAS improves, the business is healthier.
• IfPlatform ROAS diverges, optimize within the platform.
• If UTM-attributed revenue drops while spend stays flat, investigate tracking, landing pages, or funnel issues.

Common pitfalls (and how to avoid them)

• Comparing different date windows → lock a standard window for cross-platform comparison
• Ignoring refunds → decide whether you track gross or net revenue
• No UTMs → you lose cross-platform attribution in Shopify
• Counting view-through as “true sales” → keep view-through as a secondary metric
• Wrong purchase value → verify purchase event parameters and currency

Quick checklist (copy & paste)

• Same timezone / currency / date range across Shopify + ad platforms
• UTMs on every paid campaign
• Purchase event includes value + currency
• Pixel + server-side tracking enabled where possible
• One comparison attribution rule documented (e.g., 7-day click)
• Weekly report includes platform ROAS + UTM revenue + blended ROAS

FAQ

Which ROAS should I trust?

Trust ROAS for different jobs:

• Platform ROAS: best for platform optimization
• Blended ROAS / Shopify-based revenue: best for business decisions

Can I make Meta/Google/TikTok show the same ROAS?

Not realistically. But you can make your comparison consistent by standardizing UTMs, purchase value, and your reporting window.

Conclusion

Cross-platform ROAS tracking isn’t about finding one perfect number. It’s about building a system that’s consistent enough to help you decide what to scale, what to pause, and what to fix.

If you want, Bustly can unify your Shopify + ads data into one view, highlight what changed, and surface the insights that matter.