2点間の距離計算機の使い方ガイド

What This Calculator Does

This distance-between-two-points page is built for basic 2D coordinate geometry. Once you enter two points, it gives coordinate differences, straight-line distance, midpoint, and Manhattan distance together so you do not have to switch formulas in the middle of the same problem.

That makes it useful for analytic geometry, grid movement, graph sketches, and coordinate checking. Many users say they only want distance, but in practice they often need dx, dy, or midpoint immediately afterward. Showing the whole cluster is what makes the page practical.

When to Use It

• You want the straight-line distance between two points in a plane.
• You need dx, dy, and midpoint for a follow-up geometry step.
• You want to compare Euclidean distance with Manhattan distance.
• You are working on grid, graph, or beginner coordinate problems.

Inputs Explained

Point One and Point Two

The page needs the x and y coordinates of two points. Once all four values are entered, it can calculate the full result set. It accepts negative numbers and decimals, so it works for more than simple integer grid points.

Coordinate Context

The current page assumes a 2D Cartesian plane. Every output is based on ordinary flat-plane geometry. If your problem is about latitude, longitude, Earth curvature, or GPS routing, this is the wrong tool.

How the Calculation Works

The page first computes the coordinate differences dx = x2 - x1 and dy = y2 - y1. From there, it uses the standard distance formula for Euclidean distance. It also computes the midpoint coordinates and the Manhattan distance |dx| + |dy|.

That means the page tells you more than "how far." It also tells you how the points differ by direction and where the center of the segment lies. In geometry and grid problems, that broader picture is often more useful than a single number.

Example

Suppose you enter point A(0,0) and point B(3,4). The page will return dx = 3, dy = 4, Euclidean distance 5, midpoint (1.5, 2), and Manhattan distance 7.

This classic example shows why the page's grouped output is helpful: straight-line distance serves geometry, Manhattan distance fits grid-style movement, and midpoint supports segment-based follow-up work.

How to Understand the Result

dx and dy

These values are the best way to understand direction and horizontal or vertical offset. They are often the most intuitive outputs for graph interpretation.

Straight-Line Distance

This is the standard Euclidean distance, meaning the shortest line segment between the two points.

Midpoint

Midpoint is useful for segment bisectors, symmetry, graphing, and coordinate-placement tasks.

Manhattan Distance

Manhattan distance is useful for grids, step counts, and movement problems where only horizontal and vertical travel is allowed. It is not the same as straight-line distance.

Common Mistakes

• Mixing up flat-plane distance with geographic distance.
• Looking only at straight-line distance when the task really needs grid distance.
• Forgetting that dx and dy keep directional sign instead of absolute value.
• Expecting a stable result when one of the coordinates is still missing.

FAQ

Is this good for map-navigation distance?

No. Map navigation depends on roads and geographic coordinates, while this page is strictly for flat-plane Cartesian points.

Why can the midpoint contain decimals?

Because averaging two coordinates naturally produces non-integer values in many normal cases.

Which is larger, Manhattan distance or straight-line distance?

In this 2D model, Manhattan distance is usually greater than or equal to Euclidean distance.

Does it support 3D coordinates?

Not currently. The page is limited to two-dimensional points.

Notes

This tool is excellent for 2D coordinate geometry, grid problems, and classroom checking, but it is not meant for Earth-surface distance, road routing, 3D space, or physical measurement with unit conversion.

Once the problem moves beyond a flat coordinate plane, the word "distance" may imply a completely different formula.