Using Terminal
- Open Mac OS Terminal. To do it from Launchpad just type Terminal in Search bar there. You can also do it in Finder. Go to Applications and open Utilities folder there. Click on Terminal.app there.
- In Terminal window type "netstat -nr | grep default".
- Look for your router IP address after "default". See screen below for example
Using Mac OS Network Perferences
- Open Apple menu at the top left corner.
- Click on "System Preferences"
- In network settings dialog select your active connection (one with green circle in front of it) and click on "Advanced..."
- Select TCP/IP tab and look for a line with "Router" word in it. .