I'm new to QGIS so please bear with me.
I'm using QGIS 3.6. So I imported a CSV-file with latitude longitude coordinates (WGS 84), created markers and set them to have different colors (to show passing of time) and different sizes (to show precision). The accuracy is given in a column in the CSV file in meters, which need to be represented accurately on the map.
I have set it under Layer properties > Symbolizing > Categorized > Symbol > Size > Fieldtype > diameter (my own variable to show the diameter of the circle I want to draw). The problem is that the diameter isn't accurate. The sizes seem more or less correct in respect to eachother but when I use the measuring tool, the lengths are off. I have tried both to set the units as meters to scale and to set them as map units but this doesn't seem to influence the size. I have also tried to use the Assistant function and selecting the same field but even with different scaling methods I cannot get the diameters right.
So what am I doing wrong? Can anyone help me?