Cubic feet de natural gas per second to BTU (IT) per second converter on this page calculates how many BTU (IT) per second are in 'X' cubic feet de natural gas per second (where 'X' is the number of cubic feet de natural gas per second to convert to BTU (IT) per second). In order to convert a value from cubic feet de natural gas per second to BTU (IT) per second type the number of cubic feet de natural gas per second to be converted to BTU/s and then click on the 'convert' button.