Baking soda alone is not a one-for-one replacement for baking powder. Arm & Hammer and McCormick both document a combination of baking soda and cream of tartar for this direction of substitution.
A documented dry replacement
For each 1 teaspoon of baking powder, their guidance uses ¼ teaspoon baking soda plus ½ teaspoon cream of tartar. The combined volume is ¾ teaspoon; that is intentional. Do not top it up with extra soda to make a full teaspoon.
Scroll the table sideways if needed.
| Baking powder called for | Baking soda | Cream of tartar |
|---|---|---|
| ½ teaspoon | ⅛ teaspoon | ¼ teaspoon |
| 1 teaspoon | ¼ teaspoon | ½ teaspoon |
| 2 teaspoons | ½ teaspoon | 1 teaspoon |
Rows are proportional arithmetic from the cited replacement. They are not measurements of equivalent performance across different recipes.
The timing is different
Commercial double-acting baking powder supplies leavening in stages. A soda-and-cream-of-tartar mixture reacts after moistening and does not recreate the same delayed action. Have the pan and oven ready and proceed with the recipe promptly rather than planning a long hold after mixing.
This is an emergency replacement, not a guarantee of the same rise, flavor, or texture.
Check the rest of the formula
- Confirm that the missing ingredient is baking powder, not baking soda.
- Read any author-provided replacement instructions first.
- Replace only the powder amount; do not automatically remove soda already listed separately.
- Keep other ingredient changes to a minimum so the substitution remains interpretable.
If you have only baking soda
Stop before swapping equal spoonfuls. The recipe’s existing acidity does not provide a simple household calculation for how much extra soda it can support. Obtain the missing ingredient or choose a recipe designed around the ingredients available.
This page does not cover the reverse substitution, replacing baking soda with powder. Reversing a ratio here would not establish a valid recipe change.
Can I still bake without baking powder?
Only if the recipe supplies another suitable way to rise, or is designed without chemical leavening. Simply omitting the powder from a cake or quick bread is not equivalent to using the soda-and-acid method above. Choose the replacement before mixing; do not assume extra beating will compensate.
Sources & scope
Reference synthesis and arithmetic where indicated. No first-hand kitchen testing is claimed.
- Baking Soda vs. Baking PowderArm & Hammer · Accessed 2026-10-06
- Baking Powder and Baking Soda SubstitutesMcCormick · Accessed 2026-10-06