sudo mouse-dpi-tool /dev/input/event16
Mouse ThinkPad X1 Mouse on /dev/input/event16
Move the device 250mm/10in or more along the x-axis.
Pause 3 seconds before movement to reset, Ctrl+C to exit.
Covered distance in device units:     8558 at frequency 287.8Hz 	\^C
Estimated sampling frequency: 287Hz
To calculate resolution, measure physical distance covered
and look up the matching resolution in the table below
     543mm	   21.39in	     400dpi
     362mm	   14.26in	     600dpi
     271mm	   10.70in	     800dpi
     217mm	    8.56in	    1000dpi
     181mm	    7.13in	    1200dpi
     155mm	    6.11in	    1400dpi
     135mm	    5.35in	    1600dpi
     120mm	    4.75in	    1800dpi
     108mm	    4.28in	    2000dpi
      98mm	    3.89in	    2200dpi
      90mm	    3.57in	    2400dpi
If your resolution is not in the list, calculate it with:
	resolution=8558/inches, or
	resolution=8558 * 25.4/mm

Entry for hwdb match (replace XXX with the resolution in DPI):
mouse:usb:v17efp6088:name:ThinkPad X1 Mouse:
 MOUSE_DPI=XXX@287