Pinhole camera measurements?

You can make pinhole camera out of anything a black film canaster, suitcase, paint can whatever you have around your place. spray it black on the inside. For the hole which will be your shutter you need to use a small needle and you want the hole to be very small, u just press the needle but don't push it through, kinda a little prick.. you can check by going into a dark room look through the hole and see how much light you see, or test with a hallway light on and go in another room and see how much light comes in. Make sure after you have ilford paper in the container or shoe box use some black tape to cover the until you want to expose it. 40 -60 seconds isn't much time, if your doing a self- portrait it needs to be a a few minutes and you have to be really still. Something outside on a sunny day would work great but if it's cloudy you will need to expose double that amount! There isn't a measurement just use a small sewing needle and it work for you! hope this helps!