Veloviewer explorer tiles are squares on the map, when one of your activities crosses a square it is counted as a tile. (see the red squares below)


If you cross the connected left, right, top and bottom tile of a tile it is counted as a cluster-tile. (see the green square in the middle)

The max cluster is based on all the connected cluster-tiles.


The max square is based on the biggest square you can create with all the connected tiles.

You can see your tiles on the map by activating them on the "map settings" in the top right menu or via this link.

The size of a tile is about a mile square, but depends on the place on the earth. See here for the exact calculation. If you want to know more about tiles check RideEveryTile or Veloviewer