Lookalike Audience Pool Calculator

Estimate addressable reach when scaling lookalike audiences by market.

Addressable users in the country/region.
%
1% = tightest match, 10% = broadest.
Customers/leads you build the model from.
Addressable pool
1,200,000
3% lookalike
Seed quality
Usable
Ideal ≥ 5,000
Tighter 1% pool
400,000
Highest-similarity option

A 2,500 seed works but isn't robust. Your 3% lookalike spans ~1,200,000 people — start at 1–2% and widen only if it converts.

Seed purity beats seed size — a lookalike of your best-LTV customers outperforms a bigger list of all buyers.

About this calculator

Size a lookalike audience from market population and lookalike percentage, and check your seed list against the minimum needed for a clean, high-signal model.

Everything runs in your browser — nothing you type is sent anywhere or stored. Use it to sanity-check a plan, pressure-test a channel, or brief a team before you commit budget.