Paid Media

Impression Share Calculator

Impression share tells you how much of the demand you were eligible for actually saw your ad. It is the cleanest measure of headroom in a search account: how much market is sitting there that you are simply not showing up for.

Your numbers

Result

Impression share40.0%
Lost impressions270,000
Clicks left on the table9,450
Cost to capture them$22,680

FormulaImpression share = impressions received ÷ eligible impressions × 100

Worked example

180,000 impressions out of 450,000 eligible is a 40 percent impression share, so 270,000 impressions went to competitors. At a 3.5 percent click-through rate that is roughly 9,450 clicks you never got, and buying them at a $2.40 average CPC would cost about $22,680. Whether that is a bargain depends entirely on your cost per acquisition at that volume.

What to watch for

Split lost impression share by budget and by rank before acting. Lost to budget is a finance conversation, lost to rank is a relevance and bidding conversation, and treating one as the other wastes months.

One hundred percent impression share is almost never the goal. On non-brand terms the last twenty points are usually the most expensive and least qualified, and the money nearly always performs better in a different campaign.

On brand terms my view is different: if a competitor is bidding on your name, high impression share is defensive spend and I treat the cost as a tax rather than a performance line.

Frequently asked questions

What is a good impression share?

For core brand terms, aim high, typically above 85 percent. For non-brand terms, anywhere from 30 to 60 percent is normal and healthy, because the remaining inventory usually costs more than it returns.

How do I increase impression share?

If you are losing share to budget, raise the budget or narrow targeting so the money concentrates. If you are losing to rank, improve ad relevance and landing page experience first, then bids. Relevance is the cheaper lever nearly every time.

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This calculator runs entirely in your browser. Nothing you enter is sent to a server, logged, or stored. Figures are for planning and do not constitute financial advice. See disclosures.