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