This calculator requires the use of Javascript enabled and capable browsers. This script allows calculation of the meridional parts used in the construction of Mercator charts and in Mercator navigation sailing for each minute of latitude from the equator to the poles; it also calculates course and distances. On the Earth's curved surface, the distance of a degree of longitude is about the same as a degree of latitude, but only at the equator. That distance is about 60 nautical miles. The distance for a degree of longitude diminishes as it gets closer to either pole, North or South. Those poles are where all the surface meridians meet at a single point. The distance for a degree of latitude remains almost unchanged from the equator. Enter the latitude for which the meridional part is desired. Latitudes may be entered as decimal degrees by only filling in the degrees field, or as degrees and minutes, by entering the values in both fields. Then click on Calculate MP to only calculate the meridional part. For Additional information, fill out the same information for both a departure point and a destination point, both latitude and longitude. Verify or change the hemisphere selections. Click on Calculate; the meridional parts information will also be calculated so it is not required that you do an additional click on the Calculate MP buttons. Course and various distances will be displayed. You may then accumulate potential trip distance by clicking on Another Leg and entering the information ONLY in the destination. Then click on Calculate. Information for that leg and the total distances will be presented. Be aware that this calculator does not take into consideration weather, winds, magnetic deviation, currents or other navigation factors which may effect the course and ultimately, the distance. Please see our Marine Great Circle Navigation Calculator.
