How to make self-rising flour
Self-rising flour is nothing more than all-purpose flour with a leavening agent and salt already blended in. If a recipe calls for self-rising flour and you only have all-purpose, you can make your own in seconds. The standard ratio is:
1 cup all-purpose flour + 1½ teaspoons baking powder + ¼ teaspoon salt = 1 cup self-rising flour.
Whisk the baking powder and salt through the flour thoroughly before using so the leavening is evenly distributed — pockets of concentrated baking powder cause uneven rise and a bitter, metallic taste. The calculator above scales this ratio to any amount of flour, whether you measure by the cup or by weight.
The math behind it
The ratio is linear, so it scales cleanly. For every cup of flour you multiply the leavening by the same factor:
- Baking powder = 1.5 tsp × (cups of flour)
- Salt = 0.25 tsp × (cups of flour)
If you weigh your flour, use 120 g per cup (the standard King Arthur and USDA figure for all-purpose flour), so cups = grams ÷ 120. For example, 500 g of flour ≈ 4.17 cups, which needs about 6¼ tsp baking powder and about 1 tsp salt.
Common reference amounts
- 1 cup (120 g): 1½ tsp baking powder + ¼ tsp salt
- 2 cups (240 g): 1 tbsp (3 tsp) baking powder + ½ tsp salt
- 3 cups (360 g): 4½ tsp baking powder + ¾ tsp salt
- 4 cups (480 g): 2 tbsp (6 tsp) baking powder + 1 tsp salt
Tips for the best results
- Use fresh baking powder. It loses potency over time. To test it, stir ½ tsp into a little hot water — it should fizz vigorously. Flat baking powder means a flat cake or biscuit.
- Prefer aluminum-free baking powder if you can, to avoid the faintly metallic aftertaste some brands leave.
- Only mix what you need, or store the blend in an airtight container and use it within a month or two, since the baking powder slowly reacts with ambient moisture.
- Watch for double salt. If your recipe already adds salt or baking powder separately, reduce or omit those so you don't double up.