The Nissan Path

I have noticed lately that my brakes have been squealing at low speeds. I had some break dust but I did use some wheel cleaner and scrub down what I could without taking the wheels off.
I haven't replaced the pads yet, and i have put about 30k on the vehicle myself. I bought it used, so i don't know if they are original pads or ever been changed.
I took some pictures just to see if you think the pads looks thinner than normal. Im not sure if you can do a visual or if i have to actually measure, but i thought I'd try. My discs seem fine, they are smooth as glass.

*Pictures are large so you can see better up close *

They look fine.

Excessive dust can make them squeal, but so can lack of lubrication between the ends of the pads and the abutment clips.

Is there any way to give a rough idea of how many more miles are left ? I have never looked at brakes before so i am just looking to see if you all have a general idea if these look like 50k left or 10k left.

Brake wear can be affected by a number of variables, including the type of driver and whether the vehicle does a lot of long trips vs. a lot of short trips. The best thing to do is have your brakes checked at least every 15,000 miles or any time you rotate your tires.