Through hole solder pad dimension rules?
You can calculate a minimum annular ring from the hole size. If you use a 10 mil annular ring then a 25 mil hole would lead to a 45 mil pad size. 

You'd want to make it larger than that if possible if there is mechanical stress on the leads and much larger if there is mechanical stress and the PCB does not have plated-through holes. 

Generally it's a bad idea to just solder a stripped loose stranded wire into a hole in the PCB, the wire ends up breaking off just above the PCB just from a bit of handling.