Map‑based Area Calculator — Easy Polygon Drawing & CSV Upload

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Usage Guide: A Tool to Create Polygons on the Map and Calculate Their Area

This tool is a simple and convenient web application that lets you freely click on a map to draw a polygon and automatically calculate the enclosed area.

Additionally, you can upload a CSV file containing latitude and longitude coordinates that you’ve prepared in advance to instantly compute the area!

Drawing a Polygon Directly on the Map

Drag or zoom the map to display your target area.

Click on the map to plot a red dot.

As you continue clicking, the dots connect and form a polygon.

After placing at least three points, the area (in square meters, m²) is automatically calculated and displayed!

Key features:

• Area updates in real time
• Add as many points as you want
• Expand or move the area by navigating the map

Uploading an Area from a CSV File

You can also draw the area automatically by uploading a CSV file with latitude and longitude pairs!

CSV File Format:

latitude,longitude
35.681236,139.767125
35.682500,139.770000
35.680000,139.769000

Upload Steps

• Click the “Choose File” button at the top of the page.
• Select your CSV file containing latitude and longitude coordinates.
• Points will automatically plot and form a polygon, with the area displayed.
• The map will pan and zoom to fit the uploaded area.

To Reset the Drawing

Click the “Clear” button to reset and remove:

• Drawn polygon
• Plotted points
• Displayed area

This returns the page to its initial state.

Notes / Caution

The area unit is square meters (m²).

Make sure your latitude and longitude inputs are correct (CSV formatting errors may occur).

The map tiles are provided by OpenStreetMap.

Measurement accuracy is not precise surveying level — please use as reference only.