Lookalike Audience Sizer
Estimate Meta lookalike audience size at 1%, 2%, 3%, 5%, and 10% — and see whether your seed list is large enough to build on.
Your seed list
Total customer / lead rows you would upload to Meta Custom Audiences.
Drives the match rate Meta is likely to find.
10,000
50% of 20,000 uploaded. Ideal seed size — Meta has plenty of signal to build a lookalike.
Lookalike size by % in United States
1% lookalike
2,500,000
2% lookalike
5,000,000
3% lookalike
7,500,000
5% lookalike
12,500,000
10% lookalike
25,000,000
Smaller % = closer to your seed (better quality, less reach). 1–3% is typical for prospecting; 5–10% for aggressive scaling.
Country populations approximate the Meta-eligible 13+ population. Real audience sizes shown in Meta Ads Manager will be ±15% due to active-user filtering.
