Impression Share

# Impression Share

Impression Share is the percentage of total available ad impressions your ads received in a given market or auction. It’s calculated as (impressions received ÷ eligible impressions) × 100.

For example, if your Google Search campaign received 8,000 impressions but was eligible to receive 10,000 total impressions in your target geography and bid range, your Impression Share would be 80%.

Lost Impression Share (the remaining 20%) occurs due to budget constraints, low ad rank, or targeting restrictions. Monitoring this metric helps identify whether campaign underperformance stems from insufficient budget, poor bidding strategy, or limited audience reach.