From a fix on the screen to a mark on the map.
Coordinate conversion, GPS distances, bearings, map scales, polygon areas and slopes from contour lines, worked out the way a map reader does. Every calculation runs in your browser.
Coordinate Converter
Convert a position between decimal degrees, degrees-minutes-seconds, degrees and decimal minutes, and UTM grid references on the WGS84 datum.
Open → 5,554.9 kmGPS Distance Calculator
Measure the shortest distance between two coordinates on the WGS84 ellipsoid with Vincenty’s method, compared with the spherical haversine formula.
Open → 288.3° TBearing & Midpoint Calculator
Find the initial and final great-circle bearings between two coordinates, the back bearing and the midpoint, with the compass point.
Open → 1 : 24 000Map Scale Calculator
Turn a distance measured on a map into a ground distance, find the map length of a known distance, or work out an unknown scale.
Open → 352.2 haPolygon Area Calculator
Find the area and perimeter of a field, property or lake from the latitude and longitude of its corners, in square metres, hectares and acres.
Open → 10.7 %Map Slope Calculator
Work out the average grade, angle and slope ratio between two points on a topographic map from the contour interval, the contours crossed and the map distance.
Open →Positions use the WGS84 datum that GPS uses. Results are calculations from the numbers you enter, not a navigation device or a land survey: carry a map and compass outdoors, and rely on deeds and licensed surveyors for boundaries.