Kilometers per hour to nautical miles per hour conversion calculator shown above calculates how many nautical miles per hour are in 'X' kilometers per hour (where 'X' is the number of kilometers per hour to convert to nautical miles per hour). In order to convert a value from kilometers per hour to nautical miles per hour (from km/h to nmi/h) simply type the number of km/h to be converted to nmi/h and then click on the 'convert' button.