Point‑to‑Point Distance Tool

Click two locations on the map to measure the shortest path along the Earth’s surface (great‑circle distance). The line is drawn as a geodesic, so it appears correctly curved on Mercator tiles and won’t be a misleading straight line.

Distance rings for quick targeting

When you place the first pin, the map now shows adaptive distance rings around it:

• Units follow your selection (km/mi), switching to m/ft for sub‑unit values.
• At world view, rings extend to the far side of the globe (~19–20k km), so you can quickly aim for the opposite point and get the distance faster.

Notes

• Distances use the WGS‑84 mean Earth radius (6371.0088 km).
• The blue path is a great‑circle; it bends on a Mercator map because the projection flattens the globe.
• Click “Clear” to start a new measurement.

Why not a straight line?

On a Mercator map, a straight line is a rhumb line (constant compass bearing), not the shortest route. Over long distances, the shortest route is a great‑circle, which appears as a curve in Mercator. This tool computes and renders that curve so you see the physically correct path and distance.

Through Earth (straight‑line) distance vs. great‑circle distance

When people search for the “distance between two points on Earth,” there are two common interpretations:

• Great‑circle distance (on the surface): the shortest path you would travel over the Earth’s surface. This is what most maps and flights use.
• Straight‑line distance “through Earth”: the 3D chord distance passing through the Earth between the two points. It’s shorter than the surface route because it cuts through the globe.

This page shows both values. After placing two points, you’ll see the great‑circle (on‑surface) distance and the “Through Earth” straight‑line distance (the chord length). This helps with research queries like “straight line distance between cities,” “as‑the‑crow‑flies distance,” and “line of sight through Earth.”

Antipodes and the far side of the globe

Antipodes are two points exactly opposite each other on the Earth. The great‑circle distance between antipodes is about half the Earth’s circumference (~20,000 km), while the straight‑line distance through Earth is the Earth’s diameter (~12,742 km).

• Use the adaptive distance rings to target the far side of the globe quickly. At world view, rings extend to ~19–20k km so you can approach the antipodal distance with fewer guesses.
• The map labels switch units under 1 km/mi (to meters/feet), and you can toggle between km and miles at any time.

These features are helpful for queries like “antipodes map,” “find antipodal point,” “distance to the opposide side of the world,” and “calculate distance between two points on Earth.”