Apparatus, systems, articles of manufacture, and methods to identify and credit media using ratios of media characteristics are disclosed herein. An example apparatus to identify media includes a delta calculator to determine a first ratio based on a first time interval and a second time interval of a monitored media signal, and determine a second ratio based on the second time interval and a third time interval of the monitored media signal. The example apparatus also includes a signature generator to generate a monitored media ratio signature based on the first and second ratios. The example signature generator also is to initiate transmission of the monitored media ratio signature to a recipient that is to compare the monitored media ratio signature with a reference ratio signature to identify the media.