Geography & Navigation
Calculators for geographic coordinates, distances, map projections, and navigation.
Calculators & Tools
GPS Coordinate Converter
The GPS Coordinate Converter converts a single location between four coordinate formats simultaneously: decimal degrees (DD), degrees-minutes-seconds (DMS), degrees-decimal-minutes (DDM), and Universal Transverse Mercator (UTM). Enter coordinates in any one of the four tab-based input panels -- including separate degree, minute, and second fields for DMS, or zone, easting, and northing fields for UTM -- and the calculator instantly displays the equivalent values in all other formats with copy-to-clipboard buttons for each. It also shows a step-by-step breakdown of the DD-to-DMS conversion using the actual input values, a precision guide table mapping decimal places to ground accuracy (from 111 km at zero decimal places to 11.1 cm at six), and a "which format to use" label on each output row showing which devices and software expect that format. Five famous landmark presets are included for quick demonstration.
Map Scale Calculator
The Map Scale Calculator operates in four solving modes selectable by tab: Map to Real Distance (enter scale ratio and map measurement, get ground distance), Real to Map Distance (enter scale ratio and ground distance, get map measurement), Find the Scale (enter both a map measurement and its known real-world equivalent, get the scale ratio as 1:N), and Map Area to Real Area (enter scale ratio and map rectangle dimensions, get ground area using the scale-squared formula). All map measurements accept millimetres, centimetres, or inches; real distances convert to metres, kilometres, miles, feet, or nautical miles; areas output in m², km², hectares, acres, or square miles. A step-by-step formula display shows the arithmetic for each conversion using the actual input values. Eight common-scale preset buttons (1:1,000 through 1:500,000) populate the scale field instantly, and a collapsible reference table lists eleven standard scales from architectural plans (1:1,000) to continental atlas pages (1:10,000,000), showing what one centimetre represents at each scale and the typical mapping context in which each is used.
Latitude Longitude Distance Calculator
The Latitude Longitude Distance Calculator computes the straight-line (great circle) distance between two or more GPS coordinate pairs entered as decimal-degree latitude and longitude values, using the haversine formula with Earth's WGS84 mean radius. Up to eight points can be added sequentially to calculate a multi-stop route, with a per-segment breakdown table showing each leg's distance, compass bearing, direction, and percentage of the total route -- making it straightforward to detect disproportionately long segments that indicate GPS recording errors or missed waypoints. The total route distance is displayed simultaneously in kilometres, miles, and nautical miles, alongside an estimated travel time at a selectable speed (walking, cycling, driving, commercial flight, or custom km/h) and a panel showing what fraction of Earth's circumference the total distance represents. For two-point calculations, a scale reference panel shows the number of kilometres per degree of latitude and per degree of longitude at the midpoint latitude, and a haversine formula display substitutes the actual computed values for the first segment.
Great Circle Calculator
The Great Circle Calculator computes the shortest surface distance (great circle), initial bearing, final bearing, midpoint coordinates, central angle, and estimated travel time between two GPS coordinates entered as decimal-degree latitude and longitude pairs. It simultaneously calculates the rhumb line (constant-heading) distance and bearing for the same route, displays the distance difference and percentage saving in a side-by-side comparison panel, and provides a qualitative recommendation ranging from "routes nearly identical" to "great circle strongly preferred" based on the saving magnitude. Selecting "Show intermediate waypoints" generates a 10-point SLERP interpolation table showing how the compass bearing changes along the route -- the defining feature that distinguishes great circle from rhumb line navigation. Five presets cover famous aviation routes including New York to London and Los Angeles to Dubai, and distance output is switchable between km, miles, and nautical miles with a travel-time estimator offering four aircraft and vessel speed presets.
Bearing and Distance Calculator
The Bearing and Distance Calculator works in two modes. In the first mode, enter any two sets of coordinates to get the initial bearing, final bearing, back bearing, great-circle distance in kilometres, miles, and nautical miles, and the midpoint coordinates. In the second mode, enter a start point, a bearing in degrees, and a distance to calculate the exact destination coordinates and the return bearing. Use it for navigation planning, land surveying, maritime routing, flight planning, or any application that requires precise directional and distance data between geographic positions.
Antipode Calculator
The Antipode Calculator finds the exact point on Earth that is diametrically opposite any location you specify. Enter latitude and longitude in decimal degrees to get the antipodal coordinates, the straight-line distance through Earth's core (always 20,015 km / 12,437 miles), and the hemisphere of the result. Use it for geography studies, travel curiosity, or understanding how Earth's landmasses and oceans are distributed.
Declination Correction Calculator
The Declination Correction Calculator converts between true bearing (geographic North), magnetic bearing (compass-corrected for declination), and compass bearing (corrected for both declination and compass deviation). Enter any one bearing type along with the magnetic declination for your location to get all three bearing types instantly. Optional inputs include compass deviation, grid convergence for map-based navigation, and annual drift rate with years for projecting future declination. The calculator also shows the T-V-M-D-C correction chain, the East-is-least/West-is-best memory aid, and the lateral error in metres that results from ignoring the declination at your route distance.
Azimuth Calculator
The Azimuth Calculator computes the true compass bearing from one geographic coordinate to another using the atan2 formula. Enter the latitude and longitude of two points to get the azimuth in degrees (0 to 360), the back azimuth for the return trip, the 16-point compass label, quadrant bearing notation, and the great-circle distance in both kilometres and miles. Use it for navigation planning, satellite dish alignment, solar panel orientation, or any application that requires a precise compass direction between two locations.