National Public Radio (NPR) estimated its total US radio audience for Spring 2011 was over 27 million people aged 12 and older based on data from Arbitron. Arbitron is a company that provides audience measurement services and collects radio listening data for NPR and other broadcasters. The estimate was based on the broadcast times of NPR programming from midnight to midnight across all days of the week.

1. National NPR Program EstimatesSpring 2011, Total US, Persons 12+Audience Insight and ResearchSource: ACT 1 based on Arbitron Nationwide, based on program broadcast times, Monday-Sunday, Midnight to Midnight.