how can i find the gps coordinates of my lost iPhone?

Interesting problem, I played around with that and as Chris noted no clean answer.

However, if you do have "Find My iPhone" enabled on your phone, and run that app on your Mac or other device to get the dot on the map picture of where the phone is, then a somewhat clumsy workaround:

Open up Google Earth, zero in on the same location as Find iPhone shows and mouse over on that. Then GE gives you the lat/long of that position.

FWIW....

You can get lat long by inspecting the network request on chrome

Can you explain this to me a little more,, i'm not an advanced user but i'm curious how to do this.. can you help me find our coordinates by going back into my system and looking for the info? it's shut off now, the phone had battery left and i turned on "make a sound" and whom ever has it turned off the phone.. great...

You can log into www.icloud.com on a computer, or with another iPhone you can use the Find My iPhone app to locate, but the program just will show you on the map, it does not provide you with the latitude and longitude information, just a dot on the map.

Chris' post is, of course, accurate but finding the phone does require that you enabled the "Find my iPhone" function BEFORE the phone was lost.

Ah yes, one of those sometimes overlooked facts. 😝

Been there, done that and I'll do it again!