🍳

Baking Soda to Baking Powder Converter

Substitute baking soda for baking powder or the reverse — with the cream of tartar you need to turn soda into powder, and why the two are not interchangeable one-to-one.

Amount the recipe calls for

Direction

Loading calculator…

How it works

Powder → soda: soda = powder × ¼, cream of tartar = powder × ½ · Soda → powder: powder ≈ soda × 3

Baking soda is pure sodium bicarbonate and needs an acid in the recipe to release carbon dioxide, while baking powder already contains its own acid (usually cream of tartar) plus a starch. That is why the swaps are not equal: to imitate baking powder you add cream of tartar as the acid, and to replace baking soda you need about three times as much of the weaker, self-contained powder. Homemade baking powder should be mixed just before use because it activates as soon as it meets moisture.

Worked example

A recipe calls for 1 teaspoon of baking powder but you only have baking soda. Use 1/4 teaspoon of baking soda plus 1/2 teaspoon of cream of tartar (and optionally 1/4 teaspoon cornstarch), stir, and add it to the batter immediately.

Frequently asked questions

Can I just swap baking soda and baking powder one-to-one?

No. Baking soda is three to four times stronger and needs an acid already in the recipe. Using soda where powder is called for, with no added acid, leaves a soapy, metallic taste; using powder where soda is called for gives too little lift unless you triple the amount.

What does the cream of tartar do?

Cream of tartar is the acid half of baking powder. When you turn baking soda into a powder substitute, the cream of tartar supplies the acid that reacts with the soda to make carbon dioxide bubbles, giving the rise that plain soda would only produce if the recipe already contained acid.

Why use homemade powder right away?

Single-acting homemade powder begins reacting the moment it gets wet, so the gas escapes if the batter sits. Store-bought double-acting powder releases some gas when mixed and more in the oven, which is why it tolerates a short wait better.

Related calculators

Buttermilk to Milk + Acid Converter

Make a quick buttermilk substitute from regular milk and an acid — lemon juice, vinegar or cream of tartar — with the exact amounts for any quantity you need.

Self-Rising to All-Purpose Flour Converter

Convert between self-rising and all-purpose flour — add the right baking powder and salt to make self-rising, or adjust a recipe when you only have one kind.

Cake Flour Substitute Calculator

Make a cake flour substitute from all-purpose flour and cornstarch — replace 2 tablespoons per cup with cornstarch for the tender, low-protein flour cakes need.

Yeast Conversion Calculator

Convert between active dry, instant and fresh (cake) yeast in grams, ounces, teaspoons, packets or cubes. Choose the conversion rule your recipe uses, see all three yeasts at once and check the yeast against your flour.

This calculator is for educational purposes. Double-check important results before acting on them.