BTU (IT) per hour to calories per second converter above calculates how many calories per second are in 'X' BTU (IT) per hour (where 'X' is the number of BTU (IT) per hour to convert to calories per second). In order to convert a value from BTU (IT) per hour to calories per second (from BTU/h to cal/s) just type the number of BTU/h to be converted to cal/s and then click on the 'convert' button.