If you want to check your Wi-Fi stats when using your Mac, there are a few different ways to get the information you need.
One of the first options you can utilise is hold down the option key, when clicking on the menu bar icon. This will allow you to access more information in the popup display.
The other way is to open up the network control utility screen. This can be done by pressing command and space, which will open the Spotlight search box, allowing you to search for the utility. It’s also available in the applications folder, under utilities.
Another method is through applications, then utilities. There is a folder called “AirPort” where you can view various statistics regarding your networking details, including WiFi speed.