The percentage of impressions your ads received divided by the total number of impressions they were eligible to receive.
Advertisers reading about campaign performance in Google Ads or other advertising platforms.
01What it is and how it works
Impression Share (IS) is calculated as impressions received divided by eligible impressions, multiplied by 100. Eligible impressions are the total number of times your ad could have been shown based on your campaign settings — targeting, budget, bid, ad quality, and the auction environment. The metric is reported in Google Ads and other advertising platforms. It reveals how much of the available inventory you are capturing. A low IS means you are missing opportunities; a high IS means you are appearing nearly every time you are eligible. The metric is broken down further into "Lost IS (budget)" and "Lost IS (rank)" to show why you are missing impressions. Lost IS (budget) means your campaign ran out of budget before the end of the day. Lost IS (rank) means your ad rank — a combination of bid and Quality Score — was too low to win the auction.
Impression Share tells you how often your ad actually shows up compared to how often it could have shown up.
02What to do about it
Start by checking your Impression Share report in Google Ads. Look at the two lost-IS columns. If you are losing impressions due to budget, increase your daily budget or switch to an automated bidding strategy that optimizes for impression share, such as Target Impression Share. If you are losing due to rank, improve your Quality Score by tightening keyword relevance, improving ad copy, and optimizing landing pages. You can also raise your bids. Review your targeting — overly narrow audiences or locations can reduce eligible impressions and make IS misleading. Monitor IS over time, especially after changes. Use segments like device, network, or time of day to find specific areas where you are underperforming. For brand campaigns, a high IS is often desirable; for non-brand, a moderate IS may be more cost-effective.
03How it is measured or noticed
In Google Ads, Impression Share appears in the campaign, ad group, and keyword reports. You can add the columns "Impr. share", "Search lost IS (budget)", and "Search lost IS (rank)". The numbers are calculated daily and shown as percentages. You can also see Impression Share in the Auction Insights report, where it compares your share against competitors. The metric is available for Search, Display, Shopping, and Video campaigns. To notice changes, look at the trend over the last 7 or 30 days. A sudden drop may indicate budget exhaustion or a competitor entering the auction. A rise may follow a bid increase or Quality Score improvement. The data updates with a delay of a few hours.
04Common mistakes
- Assuming 100% Impression Share is always good — it can mean you are overpaying for low-value placements or wasting budget on irrelevant queries.
- Ignoring lost IS due to rank and only focusing on budget — both causes need separate fixes.
- Not segmenting by device or time — a 90% IS overall might hide a 50% IS on mobile during peak hours.
- Using Impression Share as a standalone metric — always pair it with cost, conversions, and ROAS to understand efficiency.
- Setting unrealistic targets without considering competition — in a highly competitive auction, 50% IS may be excellent.
05Limits
Impression Share only measures ad visibility, not clicks, conversions, or brand impact. A high IS does not guarantee performance. The metric is based on eligible impressions, which are estimates — the platform calculates eligibility based on your settings, but actual eligible inventory may vary. Impression Share is not meaningful for campaigns with very low traffic (fewer than a few hundred impressions per day) because small changes cause large swings. It also does not apply to non-auction placements like direct deals or programmatic guaranteed. Finally, Impression Share is often confused with Click Share (the share of clicks you receive) or Search Impression Share (which is specific to search ads). Each metric answers a different question.
06A worked example
A campaign has 10,000 eligible impressions in a day. Your ads received 6,000 impressions. Impression Share = 60%. You check the report and find 30% lost due to budget and 10% lost due to rank. You increase the daily budget by 20% and improve Quality Score from 5 to 7. The next day, Impression Share rises to 75%.
Frequently asked questions
How is Impression Share different from Click-Through Rate?
Impression Share measures how often your ad shows when it is eligible, while Click-Through Rate measures how often people click after seeing the ad. They track different stages of the funnel: visibility versus engagement.
Should I focus on increasing Impression Share if my campaign is already performing well?
It depends. If your ads are not showing as often as competitors, you might miss opportunities. But if you are already hitting budget limits or achieving your target CPA, increasing Impression Share may not be beneficial.
How do I find my Impression Share in Google Ads?
You can check the Impression Share column in your campaign, ad group, or keyword reports. It is also available under the 'Competitive metrics' section. Just add the column to your report.
Does Impression Share still matter if I'm using automated bidding?
Yes, it still matters. Automated bidding optimizes for conversions but does not guarantee your ad shows for every eligible query. Checking Impression Share helps you see if you are missing impressions that could lead to conversions.
What happens if I ignore low Impression Share?
You might be missing potential impressions, clicks, and conversions. Competitors could capture your audience, reducing your overall reach. You will notice lower traffic and possibly higher costs per click as competition increases.
How quickly does Impression Share update after I make changes?
Impression Share data updates daily in Google Ads. You should wait at least a few days after making changes to see the full impact on your share.
Asked out loud
spoken, not typedThe same term in the words somebody uses speaking to an assistant rather than typing into a box — written from the situation, which is why each one carries the situation it came from.
Usually it's because your Impression Share is low. Check your Google Ads report to see the percentage. If it's below 100%, you might need to increase budget or adjust bids to capture more eligible impressions.
That's the percentage of times your ad showed out of all times it could have. A low number means you're missing opportunities. Focus on improving it if you want more visibility for your ads.
Look at Impression Share. It tells you how often your ad shows when it's eligible. If it's low, you're not capturing all possible impressions, and you may need to increase budget or bids.