Get Center of Geometry in OpenLayers 3

Bit of a workaround but you can use the getExtent method on the geometry to set the extent on the map. I presume the center of the view will then be the center of the geometry;

Test = new ol.geom.Geometry();
map.getView().fitExtent(Test.getExtent, map.getSize());
var CenterOfGeom = map.getView().getCenter()

If you do not want to change the view (which I can imagine), you can think of a function to calculate the center of the extent. This will be easy in certain types of coordinate systems (EPSG:3857, which is meter based), but more difficult in others (EPSG:4326, based on lon/lat coords). A function which could calculate this center (in EPSG:3857) would be as following;

function getCenterOfExtent(Extent){
var X = Extent[0] + (Extent[2]-Extent[0])/2;
var Y = Extent[1] + (Extent[3]-Extent[1])/2;
return [X, Y];
}

Hope this helps!

You can get its extent center using ol.extent.getCenter. In my case I have a vector layer and I want to get the center of a feature after I click it.

So

create a simple click interaction and add it to the map

 var select = new ol.interaction.Select();
 map.addInteraction(select);

For each click...

select.on('select', function(e) {

Get the first feature that is selected, from the "selected" array. Then get its geometry, and then its extent.

Use that extent to find its center, using ol.extent.getCenter

    var aa = e.selected[0].getGeometry().getExtent();
    var oo = ol.extent.getCenter(aa);
    console.log("The center is :  "+oo); // voila!!!!

 });

The same code worked for lines, points, and polygons.

PS. The ol.extent.getCenter is stable, used in OL version 3.9.0 and version 3.10.1 and can you can find it here

You can also get the center with:

var center = e.feature.getGeometry().getCenter();

OpenLayers v 6.1.1

var center = e.feature.getGeometry().getExtent().getCenter()

If your geometry contains polygon or multipolygon, try to use ol​/geom​/Polygon.getInteriorPoint or ol​/geom​/MultiPolygon.getInteriorPoints that good to get inner point(s).

Example for Polygon

let geom = feature.getGeometry();
let polygon = geom.getPolygon(0);
let XYM = polygon.getInteriorPoint();
let coordinate = XYM.getCoordinates();