A distance factor learning device that calculates an estimated value for a distance factor based upon a distance between a plurality of current positions obtained from GPS information, a number of vehicle speed pulses obtained while the distance is traveled, and a parameter which is an error index of the estimated value for the distance factor, and that is used for a current position calculation device that calculates a current position based upon the estimated value for the distance factor, comprising: a storage device; and a continuous learning unit that updates a first estimated value for the distance factor and a first parameter, based upon a measurement quantity, which is calculated based upon the vehicle speed pulses and the GPS information, the first estimated value for the distance factor and the first parameter, characterized by a one-time learning unit that updates a second estimated value for the distance factor and a second parameter, based upon the measurement quantity, which is calculated based upon the vehicle speed pulses and the GPS information, the second estimated value for the distance factor and the second parameter; a difference calculation unit that calculates a difference between the first estimated value and the second estimated value; and an arithmetic operation control unit that overwrites the first parameter and the first estimated value at the continuous learning unit with the second parameter and the second estimated value at the one-time learning unit when the difference between the first estimated value and the second estimated value, having been calculated, is equal to or greater than a predetermined value, wherein the continuous learning unit, in response to an OFF signal output from an ignition key switch, saves the first estimated distance factor value and the first parameter into the storage device, and, upon receiving an ON signal output from the ignition key switch, the continuous learning unit reads the first estimated distance factor value and the first parameter from the storage device and starts update calculation; and wherein the one-time learning unit, in response to an ON signal output from the ignition key switch, reads a default second estimated distance factor value and a default second parameter saved in the storage device and starts update calculation. a storage device; and a continuous learning unit that updates a first estimated value for the distance factor and a first parameter, based upon a measurement quantity, which is calculated based upon the vehicle speed pulses and the GPS information, the first estimated value for the distance factor and the first parameter, characterized by a one-time learning unit that updates a second estimated value for the distance factor and a second parameter, based upon the measurement quantity, which is calculated based upon the vehicle speed pulses and the GPS information, the second estimated value for the distance factor and the second parameter; a difference calculation unit that calculates a difference between the first estimated value and the second estimated value; and an arithmetic operation control unit that overwrites the first parameter and the first estimated value at the continuous learning unit with the second parameter and the second estimated value at the one-time learning unit when the difference between the first estimated value and the second estimated value, having been calculated, is equal to or greater than a predetermined value, wherein the continuous learning unit, in response to an OFF signal output from an ignition key switch, saves the first estimated distance factor value and the first parameter into the storage device, and, upon receiving an ON signal output from the ignition key switch, the continuous learning unit reads the first estimated distance factor value and the first parameter from the storage device and starts update calculation; and wherein the one-time learning unit, in response to an ON signal output from the ignition key switch, reads a default second estimated distance factor value and a default second parameter saved in the storage device and starts update calculation.