I can't seem to get the measure tool to match up with my distance matrix tool regardless of what measurements I use. There are conflicting answers on other posts about this question. Both of my layers are on WGS84
Typically, most tools in a GIS will calculate distances in the units of the coordinate system. If they're WGS84, I suggest it's calculating distances in degrees which is nonsensical. I suggest projecting your data to a projected coordinate system which has units in metres or feet, depending on your local standard.