Google Ads Lost Impression Share (Rank) Calculator

How to calculate Search Lost IS (Rank)?

Search Lost IS (Rank) is the percentage of time your ad didn't show because of low Ad Rank, which is determined by your bid and Quality Score.

Formula: Lost IS (Rank) = 100% - Search IS% - Lost IS (Budget)%

Using the Rank Loss calculator: an example

Scenario: A campaign has 20,000 eligible impressions, 12,000 served impressions, and a 15% budget loss.

Step-by-step calculation:

• Calculate Search IS: (12,000 / 20,000) = 60%
• Identify Budget Loss: 15% (from Google Ads report)
• Subtract from 100%: 100% - 60% - 15% = 25%
• Result: Your Search Lost IS (Rank) is 25%

Frequently Asked Questions

What is a 'good' Lost IS (Rank)?

Generally, a lower percentage is better. If this number is high, you should focus on improving your Quality Score or increasing your keyword bids.

Does improving Quality Score help?

Yes, since Ad Rank is a product of Bid and Quality Score, higher quality ads can reduce Rank loss without necessarily increasing spend.

Why do I need the Budget loss metric?

Google Ads attributes all lost impressions to either Budget or Rank. To isolate Rank loss, we must first account for the impressions lost to budget constraints.