Short answer
In a Conversions campaign, Bid Cap is the most you will bid for a conversion. The system turns it into an auction bid using predicted conversion likelihood, and the auction sets your actual cost. With click billing it isn't a charged price or a guaranteed CPA, and OpenAI gives no recommended amount.
How to set it
- Work out the conversion value you can afford, for example lead value × close rate
- Start the cap near that number
- Watch delivery: a cap that is too low limits volume
- Raise it gradually rather than in big jumps
Questions
Do I pay per conversion?
No. You pay per click or per 1,000 impressions, depending on billing.
Facts checked against the sources below on 12 October 2026. Platforms change quickly: if something here no longer matches what you see, tell us and we will update it.
