Calculating area of rasters in QGIS?

I have been working with some rasters and would like to know how to calculate the area occupied by one element of a raster in QGIS?

Answer

with 3 steps you can achieve what you want:

1. Vectorize raster based on the values you want to calculate


2. Open your new vector, and create a new column. Name it 'Area'.


3. Use the field calculator to populate the column with the variable $area