Examples:

Let us count routes of protocol gated/bgp on a router:

kuznet@amber:~ $ ip ro ls proto gated/bgp | wc
   1413    9891    79010
kuznet@amber:~ $

To count the size of the routing cache, we have to use the -o option because cached attributes can take more than one line of output:

kuznet@amber:~ $ ip -o ro ls cloned | wc
   159    2543    18707
kuznet@amber:~ $