The more than 20,000 visitors to the District this week for the International AIDS Conference downtown are expected to pump more than $33 million into the local economy, according to the city’s tourism bureau.

The conference, which started July 20 and runs through Friday, has drawn more than 24,000 registered delegates so far from 183 countries. The spending estimates were based on Destination Marketing Association International’s economic impact formula, which calculates total spending based on factors that include the number of visitors, where they’re from and where the conference is located, according to Destination DC.