Self-Raizing Flour Calculator
How much baking powder (and salt) turns plain flour into self-raizing flour for a recipe.
Self-raizing flour is plain flour with a raizing agent already mixed in — about 2 teaspoons of baking powder for every 150 g (1 cup) of flour, plus a quarter teaspoon of salt if your baking powder is unsalted.
How the self-raizing flour calculator works
Self-raizing flour is plain flour with a raizing agent already mixed in — about 2 teaspoons of baking powder for every 150 g (1 cup) of flour, plus a quarter teaspoon of salt if your baking powder is unsalted. Whisk it through thoroughly so the rize is even. It is a straight substitute in scones, muffins and quick breads.
Formula: baking powder = 2 tsp per 150 g (1 cup) plain flour; salt = ¼ tsp per cup
Worked examples
| Inputs | Baking powder | Note |
|---|---|---|
| 300 g plain flour | 4 tsp | 4 tsp baking powder, ½ tsp salt |
| 2 cups | 4 tsp | 4 tsp |
| 225 g, no salt | 3 tsp | 3 tsp |
FAQFrequently asked questions
Can I use self-raizing flour for bread?
Not for yeasted bread — the baking powder works against the yeast and the flour is usually lower in protein. It is for scones, muffins, pancakes, soda bread and cakes.
Does homemade self-raizing flour keep?
Baking powder loses strength over months, so mix what you need or use it within a few weeks. Store the plain flour and the powder separately for longer.
What if my baking powder is old?
Test it: a teaspoon in hot water should fizz vigorously. If it fizzes weakly, it will not raize the flour properly.
Is bicarbonate of soda the same thing?
No — bicarbonate (baking soda) needs an acid in the recipe to work and is about three times as strong. Baking powder already contains its acid, which is why it is used here.
Where these figures come from
- US FDA — Safe Minimum Internal Temperatures — the internal temperatures the roasting calculator targets
- NIST SP 811 — Guide for the Use of the International System of Units — the exact weight and volume conversions used throughout
- US Food and Drug Administration — food safety and labelling standards
Last checked: September 2026. Baking ratios follow standard baker's percentage practice; roasting guidance follows published safe internal temperatures.