Swapping baking powder and baking soda without ruining the bake
Baking soda and baking powder both make bakes rise, but they are not interchangeable spoon for spoon. Baking soda is pure sodium bicarbonate and needs an acid in the batter to release gas. Baking powder is baking soda with a dry acid already blended in (and a little starch to keep it dry), so it works in a batter that has no acid. This baking powder to baking soda converter works out the swap for the amount in your recipe, in teaspoons, tablespoons or millilitres.
The ratios here are the household substitution rules printed by US cooperative-extension services and cookery references: one teaspoon of baking powder is about a quarter teaspoon of baking soda plus half a teaspoon of cream of tartar, and one teaspoon of baking soda is about three teaspoons of baking powder. They are good enough for pancakes, muffins, cakes and quick breads, and a test batch is the safest check.
How to use the Baking Powder to Baking Soda Converter
- Choose what your recipe calls for: baking powder (you want soda) or baking soda (you want powder).
- Type the amount as written. Fractions such as 1/2 and 1½ are understood.
- Pick the unit: teaspoon, tablespoon or millilitre.
- Read the replacement in the large result, check the notes underneath, and copy it if you need it elsewhere.
Baking Powder to Baking Soda Converter features
Both directions
Powder to soda (with or without cream of tartar) and soda to powder.
Scaled to the recipe
Any amount from a pinch to many tablespoons, in teaspoons, tablespoons or millilitres.
Kitchen fractions
Answers appear as ¼, ½, ¾ and so on, not as long decimals.
Acid reminders
Notes on when the recipe must already contain buttermilk, yogurt, lemon, vinegar or brown sugar.
The ratios at a glance
| Recipe says | Use instead | Condition |
|---|---|---|
| 1 tsp baking powder | ¼ tsp baking soda + ½ tsp cream of tartar | Works in any batter |
| 1 tsp baking powder | ¼ tsp baking soda | Only if the recipe already has an acid |
| 1 tsp baking soda | 3 tsp baking powder (up to 4) | Flavour and browning change |
| 2 tsp baking powder | ½ tsp baking soda + 1 tsp cream of tartar | Mix just before using |
Why the acid matters
When baking soda meets an acid and moisture it gives off carbon dioxide, the gas that lifts the batter. If there is no acid, the soda does not react, leaves a metallic or soapy taste and the bake browns too much, because soda raises the pH. If there is too much acid for the soda, the bake can taste sour. This is why recipes with buttermilk, yogurt, honey, molasses, cocoa or brown sugar often use soda, and recipes with only flour, milk and sugar use powder.
Most baking powder sold is double-acting: some gas is released when it gets wet and the rest in the heat of the oven. A homemade mix of soda and cream of tartar is single-acting, so mix the batter quickly and bake straight away.
Tips for good results
- Measure with proper spoons and level them off. A heaped spoon can be a third too much.
- Old baking powder loses strength. Stir a teaspoon into hot water: it should fizz at once.
- If you only have soda, add the acid in the recipe (a little lemon juice or vinegar in the milk) instead of changing the soda amount.
- For other swaps, such as buttermilk or sugar, use the ingredient substitution finder; to resize the whole recipe use the recipe scaler.
Baking Powder to Baking Soda Converter FAQ
How much baking soda replaces 1 teaspoon of baking powder?
About ¼ teaspoon of baking soda, together with ½ teaspoon of cream of tartar, or on its own if the recipe already has an acid such as buttermilk or yogurt.
How much baking powder replaces baking soda?
About three times as much: 1 teaspoon of baking soda is roughly 3 teaspoons of baking powder, and up to 4 for a weak powder.
Can I use baking soda instead of baking powder with no acid?
Not on its own. Without an acid the soda does not release its gas, and the bake tastes bitter or soapy. Add cream of tartar, lemon juice or vinegar, or buy baking powder.
What can I use instead of cream of tartar?
A little lemon juice or white vinegar works as the acid: reduce another liquid by the same amount. The amounts are less exact than with cream of tartar, so test it on a small batch.
Are baking soda and bicarbonate of soda the same?
Yes. Bicarbonate of soda, bicarb and baking soda are the same ingredient. Baking powder is a different product.
Is this exact?
No. Brands differ and baking is sensitive to acidity, so treat the result as a well-tested starting point.