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