Use 1 teaspoon of baking powder for every 100 g of plain flour to make it like self-raising flour.

Basic ratio

  • Standard DIY self-raising flour is:
    • 100 g plain flour
    • 1 level teaspoon baking powder
  • Many baking guides and tests settle around this same proportion, even though some sources suggest slightly different amounts.

Common conversions

  • 150 g flour → about 1.5 tsp baking powder.
  • 1 cup (about 120–150 g depending on how you measure) → roughly 1–1.5 tsp baking powder.
  • For 1 kg flour → about 50–55 g baking powder (around 5% by weight).

Quick examples

  • Need 200 g self-raising flour?
    • Use 200 g plain flour + 2 tsp baking powder.
  • Need 300 g self-raising flour?
    • Use 300 g plain flour + 3 tsp baking powder.

Small warning

  • Adding extra baking powder to flour that is already self-raising can make bakes taste metallic and rise then collapse, so only add baking powder when starting from plain/all-purpose flour.

Information gathered from public forums or data available on the internet and portrayed here.