Out of baking powder
Making baking powder from baking soda and cream of tartar
Updated
All three charts we use build a stand-in for baking powder from the same two pantry items, baking soda and cream of tartar. They split on the proportions, so the card below shows both versions side by side.
Illinois and Colorado State print the identical mix and both label it as a swap for double-acting baking powder. Mississippi State’s line uses more baking soda and less cream of tartar, and its row does not say double-acting.
Sources disagree · replaces 1 tsp baking powder (double-acting)
Baking soda + cream of tartar
The charts below do not print the same thing for 1 tsp of baking powder (double-acting). We show each one as printed instead of averaging them.
Illinois Extension + Colorado State Extension — less baking soda, more cream of tartar
| Amount | Ingredient | ≈ grams |
|---|---|---|
| ¼ tsp | baking soda | 1.2 g |
| ⅝ tsp | cream of tartar | 1.9 g |
- University of Illinois Extension, Substitutions for Common Ingredients (modified December 2024), p. 2 — verified 2026-09-27
- Colorado State University Extension, Ingredient Substitutions (web page) — verified 2026-09-27
Mississippi State Extension — more baking soda, less cream of tartar
| Amount | Ingredient | ≈ grams |
|---|---|---|
| ⅓ tsp | baking soda | 1.5 g |
| ½ tsp | cream of tartar | 1.5 g |
- Mississippi State University Extension, Ingredient Substitutions and Equivalents (Publication 1690, 2024), p. 2 — verified 2026-09-27
Grams are volume-to-weight estimates from USDA FoodData Central (SR Legacy): Leavening agents, baking soda — 1 tsp = 4.6 g; Leavening agents, cream of tartar — 1 tsp = 3 g. Blank means the chart does not say which kind to use, or the unit is not a volume.
Before you swap
- The charts do not say why their proportions differ. This page does not average them or pick one for you.
- Colorado State also prints a version of the mix with cornstarch added. Only Colorado State lists it, so it is not on this page.
- Colorado State and Mississippi State also pair baking soda with buttermilk or sour milk, or with vinegar or lemon juice and milk. Those versions change how much liquid the recipe needs and are not on this page yet.
How these ratios are checked: our method. Spotted a mismatch with a chart? Tell us and we will recheck the original.