posted 10-22-2007 08:39 AM
Unfortunately, that depends on the castle, when it was built, etc.As a rough rule, and working from memory of all the castles I have visited, 'proper' castles have windows that are about 1 foot wide by about 3 foot tall.
Arrow slits tend to be either a vertical slit about 2 or 3 inches wide and anything up to 6 feet tall, or a + shape usually about 2 feet wide and up to 6 feet tall (the actual opening is about 2 or 3 inches wide).
However, some castles that were built more for show tended to have larger windows. Also, the higher up the building you go, the larger the windows tend to be.
Much later castles also had ports for handguns, which were a vertical slit (much like an arrow slit, but only 2 or 3 feet long) with a circular hole at the bottom(about 4 or 5 inches wide)