Distance Calculator - Khmer Numerals

How do I measure distance on the map?

Click on the map to place waypoints. The calculator draws a path between them and shows the total distance in kilometres or miles. You can add, move, or remove waypoints at any time. The distance is calculated using the Haversine formula, which computes the shortest distance between two points on the Earth's surface accounting for the Earth's curvature — this is the standard method used in aviation, navigation, and GPS systems.

Can I calculate the area of an enclosed region?

Yes. After placing at least 3 waypoints, the calculator also shows the enclosed area in square kilometres or square miles. The area is computed using the spherical excess method on the Earth's surface, which accounts for the curvature of the Earth rather than treating it as a flat plane. This is useful for measuring land parcels, property boundaries, agricultural fields, or any enclosed geographic region.

Why is the driving distance different from the straight-line distance?

Straight-line distance (as the crow flies) is the shortest possible distance between two points, calculated using the Haversine formula on the Earth's surface. Driving distance follows roads, which are never straight. The difference can be 10–40% depending on terrain and road network. This calculator shows straight-line distance; for driving distance, use a routing service like Google Maps. For planning purposes, the straight-line distance gives you a baseline — the actual travel distance will almost always be longer.

How accurate is the Haversine distance calculation?

The Haversine formula assumes the Earth is a perfect sphere, which introduces a small error (typically less than 0.5%) compared to more complex models that account for the Earth's actual shape (an oblate spheroid). For practical purposes — measuring distances between cities, planning routes, or comparing distances — this level of accuracy is more than sufficient. The error amounts to a few metres on typical city-to-city distances.

Can I measure a multi-stop route with more than two waypoints?

Yes. You can place as many waypoints as you need by clicking on the map. The calculator sums the distance between each consecutive pair of waypoints to give you the total route distance. This is useful for planning hiking routes, measuring a running loop, or calculating the perimeter of a property boundary. You can drag any waypoint to reposition it, and the total distance updates in real time.

Does the distance calculator work offline?

The map tiles require an internet connection to load, but once the map is loaded, distance calculations are performed locally in your browser. If you need to use the tool in an area with limited connectivity, load the map for your area first while online — the distance calculation will continue to work even if the connection drops, though you will not be able to pan to new areas.

Are Khmer numerals related to Thai numerals?

Yes, both systems descend from the Pallava script of South India, which spread to Southeast Asia via trade and Buddhist scholarship. The digit shapes are visually similar — for example, Khmer 3 (២) and Thai 3 (๓) share a similar rounded form. However, they are not identical, and Cambodian readers will find Khmer numerals more natural. Use the Khmer mode for Cambodian documents and the Thai mode for Thai documents.

Input: From London to Paris (straight line)

Result: Latitude/longitude: 51.5074°N, 0.1278°W to 48.8566°N, 2.3522°E. Haversine distance: 343.5 km (213.5 miles).