I have run out of self-raising flour, but have plain flour and baking powder.  Can anyone tell me what measurement of baking powder I add to plain flour to make self-raising flour.

Thanks.
Jax :-)

Adding baking powder will not "make self raising flour" but will help what ever it is your making to rise.
Depends what your making/how much you want it to rise depending on how much baking powder you put in.
:-)

It should say on the baking powder how much to use.

   1. In a large mixing bowl, measure 6 cups of flour.
   2. Add 3 tablespoons baking powder.
   3. Add 1 tablespoon salt.
   4. Either sift together or mix with a wire whisk until well combined.
   5. Can be stored in airtight container for months.

as got from about.com

no my recipe