qgis - Create rectangular polygon with dimensions in km centered on points in point layer

Given a point layer in QGIS 3.03, I am attempting to create a second layer of square polygons with a specified length of x kilometers whose centers are the points in the first layer. What would be the best way of accomplishing this?

Answer

In QGIS 3 (I’m using 3.2.0 Bonn) you can simply use the default QGIS buffer algorithm, select your points, chose the buffer distance and select End cap style = square.

See https://docs.qgis.org/testing/en/docs/user_manual/processing_algs/qgis/vectorgeometry.html#buffer for more information.

The v.buffer algorithm from GRASS GIS offers the same option and can also be used in older versions of QGIS. See https://grass.osgeo.org/grass75/manuals/v.buffer.html for more Information.