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Plot Setting-Out Coordinate Checker

Paste setting-out coordinates in perimeter order to check dimensions, diagonals, corner angles, parallelism and squareness before points reach site.

Plot Setting-Out Coordinate Checker

Enter your data

Use consistent units and verify the point or flow direction.

No sign-in
Use one point per line. The final two numbers are read as Easting and Northing; comma, tab and space-separated data are accepted.
CSV template
Optional design checks
m
m
mm
Ā°
Inputs are processed in this browser. This calculator does not send project data to a server.

Scaled plot previewThe drawing is generated entirely in your browser.

Check before use: This is an independent calculation aid, not approved design information. Confirm inputs, units, coordinate order, tolerances and project conventions before construction or setting out.

What this coordinate checker tests

The checker treats the coordinates as a closed polygon in the order supplied. It calculates every side length and whole-circle bearing, the enclosed plan area, perimeter, centroid and internal corner angles. With exactly four points it also compares opposite sides, opposite-side directions and diagonals.

The optional expected length and width fields compare the longer and shorter opposite-side pairs against the intended plot dimensions. This is useful as an independent check before issuing a setting-out file or loading coordinates into field equipment.

How to order the points

Start at any corner and continue around the perimeter, either clockwise or counter-clockwise. Do not jump diagonally across the plot. The tool automatically closes the final side back to the first point and flags crossing sides.

side length = āˆš((Eā‚‚ āˆ’ Eā‚)Ā² + (Nā‚‚ āˆ’ Nā‚)Ā²)

Interpreting the rectangle checks

A true rectangle has four 90-degree internal angles, equal opposite sides, parallel opposite sides and equal diagonals. Real setting-out data should be assessed against the project tolerance and design intent rather than a universal threshold.

Worked example

The built-in example is a 13.839459 m by 7.977705 m rectangle. Using the example should return equal opposite sides, equal diagonals and zero angular error apart from displayed rounding.

Frequently asked questions

Does the tool upload my coordinates?

No. The calculation and drawing run locally in your browser. The site has no database and the coordinate text is not transmitted by this tool.

What coordinate format can I paste?

Use one row per point with an optional label followed by Easting and Northing. Commas, tabs, semicolons and spaces are accepted, and a normal CSV header is ignored.

Why does the checker say the polygon crosses?

The points are probably not in perimeter order. Reorder them so each row moves to the next adjacent corner rather than across a diagonal.

Can I use local or arbitrary coordinates?

Yes. The formulas use coordinate differences, so national-grid, site-grid and local coordinates all work when Easting and Northing use the same linear unit.