Baking powder vs Baking soda
They are not interchangeable cup for cup. Baking soda is pure sodium bicarbonate and needs an acid in the recipe — buttermilk, brown sugar, cocoa — to react. Baking powder already has its acid built in, so it works on its own. If a recipe calls for baking soda and you only have powder, you need about three times as much, and the result tastes saltier. Reach for soda when there is acid to spark it, powder when there is not.
At a glance
| Ingredient | Grams per cup | Type | Key trait |
|---|---|---|---|
| Baking powder | 192 g | Baking Essentials | Baking powder is measured by the teaspoon — one level teaspoon is about 4 grams. |
| Baking soda | 220 g | Baking Essentials | Baking soda is denser than baking powder — one level teaspoon is about 4.6 grams. |
How to swap baking powder and baking soda
- 1 tsp baking powder = ¼ tsp baking soda + ½ tsp cream of tartar + ¼ tsp cornstarch (King Arthur Baking)Mix and use immediately — homemade baking powder loses potency within minutes. The cornstarch prevents clumping; skip it if you don't have any.
- No clean 1:1 swap exists. In a pinch: 3 tsp baking powder per 1 tsp baking soda (King Arthur Baking)Expect different texture, more leavening aftertaste, and reduced browning. Works only if the recipe already contains an acid (buttermilk, cocoa, brown sugar, lemon juice). Baking soda is cheap, lasts indefinitely sealed, and has no perfect substitute — buying more is the real fix.
Full conversions: Baking powder converter · Baking soda converter. More swaps: Baking powder substitutes · Baking soda substitutes.
More comparisons
* Conversion figures are typical average weights for one US customary cup (236.6 ml), based on the King Arthur Baking Ingredient Weight Chart and cross-referenced with the U.S. Department of Agriculture FoodData Central database. Actual weight varies with packing, brand and humidity — see our methodology.