Every web site you visit from every device in your home connects via this single public IP address, and each one of those web sites knows your IP address and can do with it what it will. It can use your IP to track you and all the devices in your house, and even get a rough idea of your physical location.
Residential Internet connections are generally given what's called a dynamic IP, which means you are only leasing it. But even though it is only "leased", chances are that you have had it a good long while. That is because it is easier for your provider to keep leasing you the same IP. The main exception is that when you turn your Cable/DSL modem off for a certain period of time, your IP address goes into a pool, and is given to the first new client who doesn't already have one assigned. Otherwise you get it back.
Knowledge is power, and knowing your public IP address is one more tool you have in the fight to regain your privacy on the Internet. Since every web site you visit sees your public IP address, there are lots of sites that will display that to you.
NOTE: Before anyone thinks I am giving out my real IP address, I have modified the IP address as well as the longitude / latitude numbers on all the screen shots below.
One of my network engineer friends told me this site years ago and I've used it ever since. It's definitely easy to remember, and that is important when your memory is as poor as mine!
If you just want to know your IP address, even Google will tell you. Just type in "IP" and it will tell you. There's other variations it will also accept, like "my IP" and "what is my IP".
This site shows you your public IP address and also your position on Google maps. It's a little scary, huh? What's even scarier is that unlike Android devices such as your phone or tablet, a web site can often tell your physical location within a few feet without your permission, based on your IP address alone.
As with other sites, this site gives you both your public IP address and your location, but with a twist. Because different sites use slightly different methods to detect your location, some may be more accurate than others. I make no secret that I live in Spokane, WA. But notice above that whatismyip.com shows my city as Seattle, WA. A couple of the listings for this site show my correct city.
The neat thing about this site is that it will give you location data from numerous sites, some of which report longitude and latitude of your exact location.
Putting your knowledge to use
What value does knowing my IP address have for my privacy? I'm glad you asked! Knowing your public IP allows you to tell when it's changed, such as when you connect to a private VPN service. The VPN I use has servers all over the world. What that means is that I can appear to the outside world to be located wherever I choose, based on the servers available from my VPN service.
Here you can see that I connected to a server in Luxembourg. When connected to the VPN, every web site I visit sees the public IP address of the VPN server I connected to, and not my actual public IP. Now any web server which tries to use geolocation data based on my IP is going to guess wrong. If you use your imagination, you will see how a VPN could be helpful to your privacy!