i need self rasing whole meal flour i only have very strong wholemeal flour

[misdee]

can i add baking powder to this?

Yes. It won't be quite the same but it will work.

so its 4oz of flour i need, how much baking powder?

It depends what you are making.

this

I normally use a teaspoon or two per 100g for regular plain to rise

I would say between 1.5 and 2, judging by what it says on the pot.

Teaspoons that is!