Baking Powder: Cups to Grams

Four grams a teaspoon — if the teaspoon is level

King Arthur's chart builds baking powder from the bottom up: 4 g per teaspoon, which multiplies out to 12 g per tablespoon and 192 g per cup. Almost nobody measures the cup; the cup figure is here for bulk baking and for the converter's completeness. What actually decides cakes is the teaspoon, and the teaspoon only holds 4 g when it is filled and levelled the disciplined way — dip the spoon into the tin, then sweep the back of a knife across it, exactly once. A casually heaped teaspoon can carry far more than 4 g of powder, and double leavener doesn't mean double rise: it means a batter that surges, collapses, and tastes faintly of soap and metal.

The flip side is old powder. Baking powder is a complete leavening system — acid and alkali pre-mixed with starch to keep them apart — and it weakens as it absorbs moisture from the kitchen air. The traditional check needs no scale: stir a little powder into a splash of hot water. Fresh powder fizzes vigorously on contact; a lazy bubble or two means the tin is done, and no conversion table can rescue the cake. Keep the tin sealed, dry, and away from the kettle's steam.

Baking powder is not baking soda

The two are confused constantly, so, plainly: baking powder is a complete system — it contains its own acid and only needs liquid and heat to work. Baking soda is a single ingredient (an alkali) that needs an acid elsewhere in the recipe — buttermilk, yogurt, cocoa, honey — to react with. They are not interchangeable by volume or by weight, and a recipe's choice between them is chemistry, not preference. Our source chart lists baking powder but does not list baking soda, so — by this site's rule of no sourced number, no number — there is no soda figure on this page or anywhere in the converter. If your recipe uses soda and gives a weight, use the recipe's weight; if it gives teaspoons, measure them level and resist the urge to convert via powder.

Where powder and this site's other small-ingredient pages overlap: the converter above also carries table salt (the other levelling-critical teaspoon) and cornstarch, the starch that keeps baking powder dry in the tin and turns up beside it in half the cakes ever written.

Frequently asked questions

Related pages

• Table salt: cups to grams — the other teaspoon where level versus heaped changes the bake
• Cake flour: cups to grams — most baking powder is spent leavening cake flour
• Cocoa powder: cups to grams — natural cocoa is an acid that leavening choices have to reckon with