Head over to any "SteamID Finder" page. You can google it or use the default one: https://www.steamidfinder.com/
To get your profile link, simply head over to your profile on Steam and click your profile link:
In this case, the steamID is already displayed at the end of the link (76561198063677912)
If you have a customized profile link, then continue with the next step below
Copy-paste the steam profile link into the site and hit search:
That's it! Your SteamID64 is now displayed!
