Distance Between Points Calculator

Measuring the straight-line gap between two points is a routine need across navigation, engineering, and urban planning. This calculator works on a flat plane: enter two points (x1, y1) and (x2, y2), and it returns the distance between them, the midpoint, and the horizontal and vertical differences (dx and dy).

The method is the Pythagorean theorem, carried into more than one dimension. For two points in 2D, (x1, y1) and (x2, y2), the distance is D = sqrt((x2 - x1)^2 + (y2 - y1)^2). The calculator has no z inputs; for points in 3D space the same idea extends to D = sqrt((x2 - x1)^2 + (y2 - y1)^2 + (z2 - z1)^2), so square the calculator's 2D distance, add (z2 - z1)^2 and take the square root. The midpoint is ((x1 + x2)/2, (y1 + y2)/2).

Keep every coordinate in the same unit; pairing meters with kilometers will throw the answer off entirely. The classic slips in doing this by hand are forgetting to square each difference before adding them, or skipping the final square root, both of which the calculator handles for you. What it can't catch is a mistyped coordinate, so give your inputs a second look before relying on the result.