As someone who does a lot of portable operations, I find myself trying to determine what Grid Square I might be operating from. Although I do not change CQ/ITU Zones frequently, sometimes I like to look at those as well.
I have some mobile tools on my phone for when I am on-site, but when scouting out locations, I prefer to use a web based tool on my computer.
The best tool that I have found for determining these is located at: https://zone-check.eu/
This website allows you to click anywhere on the map and it will tell you what the Grid Square, CQ Zone, and ITU Zone is. On the top right-hand side (Options), you can also choose to see the zone boundaries. In this example, I have turned on the CQ Zone boundaries.
Won’t display zone numbers on map while using mobile.