# How to calculate polygon areas and perimeters using QGIS?

Using QGIS, if I load a polygon layer and make a new column, how do I fill that column with the:

1. area of each polygon and another column with
2. length of the perimeter of each polygon?
• so, I have changed and saved the shapefile in the projection UTM to get meter squared area but i am still get a low decimal value for the area. For example, a polygon that is 102 km2 is showing up in the attribute table at 0.0102. I have used both methods fTools and the calculator in the attribute table. What am I doing wrong? Thanks
– user21644
Sep 2, 2013 at 22:03
• I was also seeing absurdly low numbers, but I think it was because I had the wrong CRS. I clicked the icon in the bottom right and changed the CRS and the numbers started to look better after that. Sep 20, 2013 at 5:11
• similar question: gis.stackexchange.com/q/23355/4630 Oct 27, 2014 at 10:54
• In Qgis 2.19, there is no Geometry tools in Vector menu.. Do I have to download it? Thanks for you answer Jun 21, 2017 at 17:55
• If you have a question similar to this one, create a new question. This is for answers to the original question. Jun 21, 2017 at 18:06

Open field calculator, select the new column and type the following expression

• For area: \$area
• For perimeter: \$perimeter

Make sure your layer is in a projected coordinate system (not lat/long ) and in correct units. ( i.e. if your layer's projection has 'meters' as units, your area will be square meters ) Note that reprojecting layers on-the-fly does not change the units for area/perimeter calculation, so you have to first reproject using Save as ... with the correct target CRS.  • Are there other functions that begin with \$? Jul 24, 2012 at 4:58
• Many actually, you'll see them in the field calculator. in QGIS 1.8, it's nicely organized under 'function list' in field calculator Jul 24, 2012 at 5:49

You also can use fTools: Vector menu -> Geometry Tools -> Export/Add geometry columns