Baking Soda and Baking Powder Calculator

Baking soda and baking powder both produce carbon dioxide bubbles to leaven baked goods, but they work differently and are not a 1:1 swap.

Baking soda (sodium bicarbonate) is pure base. It needs an acid in the recipe to activate — buttermilk, yogurt, vinegar, lemon juice, brown sugar, or cocoa powder. Without acid, it just sits there and adds a soapy taste.

Baking powder is baking soda plus a dry acid (usually cream of tartar or sodium aluminum sulfate) plus cornstarch. It reacts in two stages: once when wet, again when heated. That is why it is called “double-acting.”

The conversion ratio: 1 tsp baking soda = 3 tsp baking powder

This means baking soda is about three times as powerful per teaspoon. Most recipes call for more baking powder than soda because the combined leavener in powder is diluted.

Substituting soda for powder: Divide the baking powder amount by 3 to get baking soda. But you now have no acid source. Add 1/2 tsp cream of tartar per 1/4 tsp baking soda, or use buttermilk in place of regular milk.

Substituting powder for soda: Multiply baking soda amount by 3. If the recipe had an acid in it (buttermilk, vinegar), you may want to replace that with a neutral liquid — milk, water — since the powder supplies its own acid. The result will taste less tangy.

Recipes that call for both: some recipes use a small amount of soda to neutralize excess acid (giving a milder flavor) while baking powder handles the majority of leavening. This is intentional and common in chocolate cake recipes.