Attribution Window: What It Means for Your Ad Results

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An attribution window is the time limit an ad platform uses to decide whether a sale counts as a result of your ad. If someone clicks your Meta ad and buys three days later, a 7-day click attribution window credits the ad with that sale. A 1-day click window does not.

Windows come in two kinds. Click-through windows count purchases after someone clicked the ad. View-through windows count purchases after someone saw the ad but did not click. Understanding both explains why Ads Manager, Google Analytics and Shopify rarely agree on how many sales your ads drove.

What is an attribution window?

An attribution window is the period after someone clicks or views an ad during which a purchase is credited to that ad. On Meta, a common setting is 7-day click and 1-day view. Longer windows credit more sales to ads, shorter windows credit fewer, so the window you choose changes reported ROAS.

Attribution window (Conversion window): An attribution window is the period after an ad click or view during which a purchase is credited to that ad by the ad platform.

How attribution windows work and how to read them

There is no formula in the usual sense. The window is a rule: count a conversion if it happens within X days of a click or Y days of a view. Meta lets you choose the setting used to optimise and report a campaign, and you can compare windows side by side in Ads Manager to see how results change.

Worked example (illustrative numbers): a campaign spends $5,000. Under 7-day click, Meta reports 100 purchases. Under 1-day click, it reports 70. With a $90 average order value, 7-day click ROAS is $9,000 divided by $5,000, or 1.8x. 1-day click ROAS is $6,300 divided by $5,000, or 1.26x.

Nothing about the campaign changed. Only the counting rule did. That is why you should always state the window next to any ROAS figure, and why comparing campaigns reported on different windows is misleading.

What the right window depends on

No single window is correct for every brand. The best choice reflects how long your customers usually take to decide, and how much you trust view-through credit. A low-priced impulse product may sell mostly within a day of the click, while a premium item may take a week or more of consideration. Key factors are:

Consideration time: higher priced products usually justify a longer click window.
Purchase cycle: repeat and replenishment buyers often convert quickly.
Role of view-through: video-heavy accounts may see many view-through conversions, some of which would have happened anyway.
Optimisation signal: the window affects which conversions Meta learns from, not just what it reports.
Reporting consistency: your team and any agency should use the same window when comparing results.

How to use attribution windows well

Pick one standard window for optimisation and reporting, then stick with it so results are comparable over time. Many DTC brands use 7-day click with 1-day view as the default and also look at 1-day click as a stricter view.

Check the gap between click and view results. If a large share of reported purchases comes from 1-day view, test whether those sales are incremental, for example by watching what happens to store revenue when spend changes. Pair platform data with store-level metrics such as blended ROAS and MER, which do not depend on attribution at all. And make sure your pixel and Conversions API are reporting cleanly, because a perfect window is useless if events go missing. Our guide to what ROAS means explains how to read platform ROAS against these store numbers.

Common attribution window mistakes

Comparing ROAS from campaigns or reports that use different windows.
Switching windows to make results look better before a review.
Treating every view-through conversion as fully caused by the ad.
Expecting Meta, Google and Shopify numbers to match when each uses different attribution rules.
Ignoring that Meta optimises toward the conversions counted in its window, so the setting affects delivery too.

Related terms

The Conversions API decides how many events reach Meta in the first place, while the attribution window decides which of them get credited to ads. Blended ROAS and MER give you a view that sits outside any platform's window, which makes them the best cross-check.

A useful habit is to keep a single reporting sheet that records platform ROAS on your standard window next to blended ROAS for the same week. Over a few months you will see how much platform reporting tends to over or under count relative to the store, and you can adjust targets accordingly. That ratio is far more useful than arguing about which window is right.

Proof from real accounts

$50M+ Meta ad spend managed: Across our client accounts over 12+ years
4.51x ROAS in 17 days: $52,000 on $11,586 spend, supplement brand (see the proof)
3.64x ROAS in 27 days: $146,184 on $40,124 spend, skincare brand (see the proof)

Frequently asked questions

What is the default attribution window on Meta?

For most sales campaigns Meta uses 7-day click and 1-day view as the standard setting. That means a purchase is credited if it happens within seven days of a click or one day of a view. You can compare other windows in Ads Manager reporting to see how results change, which helps you judge how much credit is coming from views.

Should I use 1-day click or 7-day click?

It depends on how long your customers take to buy. A 7-day click window suits products with some consideration time, while 1-day click gives a stricter, more conservative view. Many brands optimise on 7-day click and also review 1-day click results. Whatever you choose, use it consistently so results can be compared over time.

Why does Shopify show different sales than Meta?

Shopify counts every order, while Meta counts only orders it can link to an ad within its attribution window. Meta may also credit a sale that another channel helped drive, and miss sales where tracking failed. Different windows and models mean the numbers will never match exactly. Blended ROAS is the best way to reconcile them.

Are view-through conversions real?

Some are and some are not. A person who saw your video and bought later may well have been influenced by it, but they may also have bought anyway. View-through credit is most reliable when you can see store revenue move with ad spend. Treat a high share of view-through conversions as a prompt to test incrementality, not as proof.

Does the attribution window change how Meta delivers ads?

Yes. Meta optimises toward the conversions counted in the window you choose, so the setting influences which people it looks for. A shorter window pushes it toward fast buyers, while a longer one gives credit to slower purchase journeys. That is why changing the window can affect results, not only reporting, and why it should not be changed often.

Not sure which numbers to trust?

In a Brand Growth Audit we compare your platform reporting, tracking setup and store revenue so you know what your ads are really driving. Book a Brand Growth Audit.